| 1 | <!DOCTYPE html |
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| 2 | PUBLIC "-//W3C//DTD HTML 4.01//EN"> |
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| 3 | <html lang="en"> |
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| 4 | <head profile="http://www.w3.org/2006/03/hcard http://dublincore.org/documents/2008/08/04/dc-html/"> |
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| 5 | <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> |
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| 6 | <title>HTTP/1.1, part 3: Message Payload and Content Negotiation</title><style type="text/css" title="Xml2Rfc (sans serif)"> |
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| 7 | a { |
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| 8 | text-decoration: none; |
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| 9 | } |
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| 10 | a.smpl { |
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| 11 | color: black; |
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| 12 | } |
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| 13 | a:hover { |
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| 14 | text-decoration: underline; |
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| 15 | } |
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| 16 | a:active { |
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| 17 | text-decoration: underline; |
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| 18 | } |
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| 19 | address { |
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| 20 | margin-top: 1em; |
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| 21 | margin-left: 2em; |
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| 22 | font-style: normal; |
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| 23 | } |
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| 24 | body { |
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| 25 | color: black; |
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| 26 | font-family: verdana, helvetica, arial, sans-serif; |
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| 27 | font-size: 10pt; |
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| 28 | } |
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| 29 | cite { |
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| 30 | font-style: normal; |
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| 31 | } |
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| 32 | div.note { |
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| 33 | margin-left: 2em; |
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| 34 | } |
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| 35 | dd { |
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| 36 | margin-right: 2em; |
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| 37 | } |
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| 38 | dl { |
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| 39 | margin-left: 2em; |
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| 40 | } |
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| 41 | |
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| 42 | ul.empty { |
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| 43 | list-style-type: none; |
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| 44 | } |
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| 45 | ul.empty li { |
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| 46 | margin-top: .5em; |
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| 47 | } |
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| 48 | dl p { |
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| 49 | margin-left: 0em; |
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| 50 | } |
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| 51 | dt { |
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| 52 | margin-top: .5em; |
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| 53 | } |
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| 54 | h1 { |
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| 55 | font-size: 14pt; |
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| 56 | line-height: 21pt; |
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| 57 | page-break-after: avoid; |
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| 58 | } |
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| 59 | h1.np { |
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| 60 | page-break-before: always; |
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| 61 | } |
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| 62 | h1 a { |
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| 63 | color: #333333; |
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| 64 | } |
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| 65 | h2 { |
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| 66 | font-size: 12pt; |
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| 67 | line-height: 15pt; |
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| 68 | page-break-after: avoid; |
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| 69 | } |
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| 70 | h3, h4, h5, h6 { |
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| 71 | font-size: 10pt; |
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| 72 | page-break-after: avoid; |
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| 73 | } |
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| 74 | h2 a, h3 a, h4 a, h5 a, h6 a { |
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| 75 | color: black; |
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| 76 | } |
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| 77 | img { |
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| 78 | margin-left: 3em; |
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| 79 | } |
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| 80 | li { |
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| 81 | margin-left: 2em; |
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| 82 | margin-right: 2em; |
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| 83 | } |
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| 84 | ol { |
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| 85 | margin-left: 2em; |
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| 86 | margin-right: 2em; |
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| 87 | } |
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| 88 | ol.la { |
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| 89 | list-style-type: lower-alpha; |
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| 90 | } |
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| 91 | ol.ua { |
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| 92 | list-style-type: upper-alpha; |
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| 93 | } |
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| 94 | ol p { |
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| 95 | margin-left: 0em; |
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| 96 | } |
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| 97 | p { |
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| 98 | margin-left: 2em; |
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| 99 | margin-right: 2em; |
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| 100 | } |
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| 101 | pre { |
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| 102 | margin-left: 3em; |
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| 103 | background-color: lightyellow; |
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| 104 | padding: .25em; |
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| 105 | } |
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| 106 | pre.text2 { |
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| 107 | border-style: dotted; |
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| 108 | border-width: 1px; |
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| 109 | background-color: #f0f0f0; |
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| 110 | width: 69em; |
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| 111 | } |
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| 112 | pre.inline { |
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| 113 | background-color: white; |
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| 114 | padding: 0em; |
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| 115 | } |
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| 116 | pre.text { |
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| 117 | border-style: dotted; |
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| 118 | border-width: 1px; |
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| 119 | background-color: #f8f8f8; |
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| 120 | width: 69em; |
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| 121 | } |
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| 122 | pre.drawing { |
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| 123 | border-style: solid; |
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| 124 | border-width: 1px; |
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| 125 | background-color: #f8f8f8; |
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| 126 | padding: 2em; |
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| 127 | } |
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| 128 | table { |
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| 129 | margin-left: 2em; |
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| 130 | } |
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| 131 | table.tt { |
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| 132 | vertical-align: top; |
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| 133 | } |
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| 134 | table.full { |
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| 135 | border-style: outset; |
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| 136 | border-width: 1px; |
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| 137 | } |
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| 138 | table.headers { |
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| 139 | border-style: outset; |
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| 140 | border-width: 1px; |
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| 141 | } |
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| 142 | table.tt td { |
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| 143 | vertical-align: top; |
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| 144 | } |
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| 145 | table.full td { |
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| 146 | border-style: inset; |
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| 147 | border-width: 1px; |
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| 148 | } |
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| 149 | table.tt th { |
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| 150 | vertical-align: top; |
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| 151 | } |
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| 152 | table.full th { |
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| 153 | border-style: inset; |
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| 154 | border-width: 1px; |
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| 155 | } |
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| 156 | table.headers th { |
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| 157 | border-style: none none inset none; |
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| 158 | border-width: 1px; |
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| 159 | } |
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| 160 | table.left { |
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| 161 | margin-right: auto; |
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| 162 | } |
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| 163 | table.right { |
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| 164 | margin-left: auto; |
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| 165 | } |
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| 166 | table.center { |
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| 167 | margin-left: auto; |
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| 168 | margin-right: auto; |
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| 169 | } |
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| 170 | caption { |
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| 171 | caption-side: bottom; |
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| 172 | font-weight: bold; |
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| 173 | font-size: 9pt; |
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| 174 | margin-top: .5em; |
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| 175 | } |
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| 176 | |
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| 177 | table.header { |
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| 178 | border-spacing: 1px; |
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| 179 | width: 95%; |
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| 180 | font-size: 10pt; |
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| 181 | color: white; |
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| 182 | } |
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| 183 | td.top { |
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| 184 | vertical-align: top; |
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| 185 | } |
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| 186 | td.topnowrap { |
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| 187 | vertical-align: top; |
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| 188 | white-space: nowrap; |
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| 189 | } |
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| 190 | table.header td { |
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| 191 | background-color: gray; |
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| 192 | width: 50%; |
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| 193 | } |
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| 194 | table.header a { |
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| 195 | color: white; |
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| 196 | } |
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| 197 | td.reference { |
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| 198 | vertical-align: top; |
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| 199 | white-space: nowrap; |
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| 200 | padding-right: 1em; |
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| 201 | } |
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| 202 | thead { |
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| 203 | display:table-header-group; |
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| 204 | } |
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| 205 | ul.toc, ul.toc ul { |
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| 206 | list-style: none; |
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| 207 | margin-left: 1.5em; |
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| 208 | margin-right: 0em; |
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| 209 | padding-left: 0em; |
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| 210 | } |
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| 211 | ul.toc li { |
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| 212 | line-height: 150%; |
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| 213 | font-weight: bold; |
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| 214 | font-size: 10pt; |
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| 215 | margin-left: 0em; |
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| 216 | margin-right: 0em; |
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| 217 | } |
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| 218 | ul.toc li li { |
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| 219 | line-height: normal; |
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| 220 | font-weight: normal; |
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| 221 | font-size: 9pt; |
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| 222 | margin-left: 0em; |
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| 223 | margin-right: 0em; |
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| 224 | } |
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| 225 | li.excluded { |
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| 226 | font-size: 0pt; |
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| 227 | } |
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| 228 | ul p { |
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| 229 | margin-left: 0em; |
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| 230 | } |
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| 231 | ul.ind, ul.ind ul { |
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| 232 | list-style: none; |
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| 233 | margin-left: 1.5em; |
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| 234 | margin-right: 0em; |
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| 235 | padding-left: 0em; |
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| 236 | page-break-before: avoid; |
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| 237 | } |
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| 238 | ul.ind li { |
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| 239 | font-weight: bold; |
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| 240 | line-height: 200%; |
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| 241 | margin-left: 0em; |
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| 242 | margin-right: 0em; |
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| 243 | } |
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| 244 | ul.ind li li { |
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| 245 | font-weight: normal; |
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| 246 | line-height: 150%; |
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| 247 | margin-left: 0em; |
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| 248 | margin-right: 0em; |
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| 249 | } |
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| 250 | .avoidbreak { |
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| 251 | page-break-inside: avoid; |
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| 252 | } |
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| 253 | .bcp14 { |
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| 254 | font-style: normal; |
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| 255 | text-transform: lowercase; |
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| 256 | font-variant: small-caps; |
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| 257 | } |
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| 258 | .comment { |
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| 259 | background-color: yellow; |
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| 260 | } |
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| 261 | .center { |
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| 262 | text-align: center; |
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| 263 | } |
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| 264 | .error { |
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| 265 | color: red; |
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| 266 | font-style: italic; |
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| 267 | font-weight: bold; |
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| 268 | } |
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| 269 | .figure { |
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| 270 | font-weight: bold; |
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| 271 | text-align: center; |
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| 272 | font-size: 9pt; |
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| 273 | } |
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| 274 | .filename { |
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| 275 | color: #333333; |
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| 276 | font-weight: bold; |
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| 277 | font-size: 12pt; |
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| 278 | line-height: 21pt; |
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| 279 | text-align: center; |
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| 280 | } |
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| 281 | .fn { |
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| 282 | font-weight: bold; |
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| 283 | } |
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| 284 | .hidden { |
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| 285 | display: none; |
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| 286 | } |
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| 287 | .left { |
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| 288 | text-align: left; |
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| 289 | } |
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| 290 | .right { |
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| 291 | text-align: right; |
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| 292 | } |
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| 293 | .title { |
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| 294 | color: #990000; |
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| 295 | font-size: 18pt; |
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| 296 | line-height: 18pt; |
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| 297 | font-weight: bold; |
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| 298 | text-align: center; |
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| 299 | margin-top: 36pt; |
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| 300 | } |
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| 301 | .vcardline { |
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| 302 | display: block; |
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| 303 | } |
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| 304 | .warning { |
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| 305 | font-size: 14pt; |
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| 306 | background-color: yellow; |
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| 307 | } |
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| 308 | |
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| 309 | |
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| 310 | @media print { |
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| 311 | .noprint { |
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| 312 | display: none; |
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| 313 | } |
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| 314 | |
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| 315 | a { |
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| 316 | color: black; |
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| 317 | text-decoration: none; |
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| 318 | } |
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| 319 | |
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| 320 | table.header { |
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| 321 | width: 90%; |
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| 322 | } |
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| 323 | |
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| 324 | td.header { |
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| 325 | width: 50%; |
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| 326 | color: black; |
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| 327 | background-color: white; |
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| 328 | vertical-align: top; |
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| 329 | font-size: 12pt; |
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| 330 | } |
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| 331 | |
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| 332 | ul.toc a::after { |
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| 333 | content: leader('.') target-counter(attr(href), page); |
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| 334 | } |
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| 335 | |
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| 336 | ul.ind li li a { |
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| 337 | content: target-counter(attr(href), page); |
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| 338 | } |
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| 339 | |
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| 340 | .print2col { |
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| 341 | column-count: 2; |
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| 342 | -moz-column-count: 2; |
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| 343 | column-fill: auto; |
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| 344 | } |
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| 345 | } |
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| 346 | |
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| 347 | @page { |
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| 348 | @top-left { |
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| 349 | content: "Internet-Draft"; |
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| 350 | } |
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| 351 | @top-right { |
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| 352 | content: "October 2011"; |
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| 353 | } |
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| 354 | @top-center { |
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| 355 | content: "HTTP/1.1, Part 3"; |
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| 356 | } |
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| 357 | @bottom-left { |
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| 358 | content: "Fielding, et al."; |
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| 359 | } |
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| 360 | @bottom-center { |
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| 361 | content: "Expires May 3, 2012"; |
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| 362 | } |
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| 363 | @bottom-right { |
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| 364 | content: "[Page " counter(page) "]"; |
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| 365 | } |
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| 366 | } |
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| 367 | |
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| 368 | @page:first { |
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| 369 | @top-left { |
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| 370 | content: normal; |
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| 371 | } |
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| 372 | @top-right { |
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| 373 | content: normal; |
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| 374 | } |
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| 375 | @top-center { |
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| 376 | content: normal; |
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| 377 | } |
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| 378 | } |
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| 379 | </style><link rel="Contents" href="#rfc.toc"> |
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| 380 | <link rel="Author" href="#rfc.authors"> |
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| 381 | <link rel="Copyright" href="#rfc.copyrightnotice"> |
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| 382 | <link rel="Index" href="#rfc.index"> |
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| 383 | <link rel="Chapter" title="1 Introduction" href="#rfc.section.1"> |
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| 384 | <link rel="Chapter" title="2 Protocol Parameters" href="#rfc.section.2"> |
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| 385 | <link rel="Chapter" title="3 Payload" href="#rfc.section.3"> |
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| 386 | <link rel="Chapter" title="4 Representation" href="#rfc.section.4"> |
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| 387 | <link rel="Chapter" title="5 Content Negotiation" href="#rfc.section.5"> |
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| 388 | <link rel="Chapter" title="6 Header Field Definitions" href="#rfc.section.6"> |
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| 389 | <link rel="Chapter" title="7 IANA Considerations" href="#rfc.section.7"> |
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| 390 | <link rel="Chapter" title="8 Security Considerations" href="#rfc.section.8"> |
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| 391 | <link rel="Chapter" title="9 Acknowledgments" href="#rfc.section.9"> |
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| 392 | <link rel="Chapter" href="#rfc.section.10" title="10 References"> |
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| 393 | <link rel="Appendix" title="A Differences between HTTP and MIME" href="#rfc.section.A"> |
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| 394 | <link rel="Appendix" title="B Additional Features" href="#rfc.section.B"> |
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| 395 | <link rel="Appendix" title="C Changes from RFC 2616" href="#rfc.section.C"> |
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| 396 | <link rel="Appendix" title="D Collected ABNF" href="#rfc.section.D"> |
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| 397 | <link rel="Appendix" title="E Change Log (to be removed by RFC Editor before publication)" href="#rfc.section.E"> |
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| 398 | <meta name="generator" content="http://greenbytes.de/tech/webdav/rfc2629.xslt, Revision 1.556, 2011-08-28 20:30:48, XSLT vendor: SAXON 8.9 from Saxonica http://www.saxonica.com/"> |
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| 399 | <link rel="schema.dct" href="http://purl.org/dc/terms/"> |
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| 400 | <meta name="dct.creator" content="Fielding, R."> |
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| 401 | <meta name="dct.creator" content="Gettys, J."> |
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| 402 | <meta name="dct.creator" content="Mogul, J."> |
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| 403 | <meta name="dct.creator" content="Frystyk, H."> |
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| 404 | <meta name="dct.creator" content="Masinter, L."> |
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| 405 | <meta name="dct.creator" content="Leach, P."> |
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| 406 | <meta name="dct.creator" content="Berners-Lee, T."> |
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| 407 | <meta name="dct.creator" content="Lafon, Y."> |
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| 408 | <meta name="dct.creator" content="Reschke, J. F."> |
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| 409 | <meta name="dct.identifier" content="urn:ietf:id:draft-ietf-httpbis-p3-payload-latest"> |
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| 410 | <meta name="dct.issued" scheme="ISO8601" content="2011-10-31"> |
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| 411 | <meta name="dct.replaces" content="urn:ietf:rfc:2616"> |
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| 412 | <meta name="dct.abstract" content="The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypertext information systems. HTTP has been in use by the World Wide Web global information initiative since 1990. This document is Part 3 of the seven-part specification that defines the protocol referred to as "HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 3 defines HTTP message content, metadata, and content negotiation."> |
|---|
| 413 | <meta name="description" content="The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypertext information systems. HTTP has been in use by the World Wide Web global information initiative since 1990. This document is Part 3 of the seven-part specification that defines the protocol referred to as "HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 3 defines HTTP message content, metadata, and content negotiation."> |
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| 414 | </head> |
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| 415 | <body> |
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| 416 | <table class="header"> |
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| 417 | <tbody> |
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| 418 | <tr> |
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| 419 | <td class="left">HTTPbis Working Group</td> |
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| 420 | <td class="right">R. Fielding, Editor</td> |
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| 421 | </tr> |
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| 422 | <tr> |
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| 423 | <td class="left">Internet-Draft</td> |
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| 424 | <td class="right">Adobe</td> |
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| 425 | </tr> |
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| 426 | <tr> |
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| 427 | <td class="left">Obsoletes: <a href="http://tools.ietf.org/html/rfc2616">2616</a> (if approved) |
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| 428 | </td> |
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| 429 | <td class="right">J. Gettys</td> |
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| 430 | </tr> |
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| 431 | <tr> |
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| 432 | <td class="left">Intended status: Standards Track</td> |
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| 433 | <td class="right">Alcatel-Lucent</td> |
|---|
| 434 | </tr> |
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| 435 | <tr> |
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| 436 | <td class="left">Expires: May 3, 2012</td> |
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| 437 | <td class="right">J. Mogul</td> |
|---|
| 438 | </tr> |
|---|
| 439 | <tr> |
|---|
| 440 | <td class="left"></td> |
|---|
| 441 | <td class="right">HP</td> |
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| 442 | </tr> |
|---|
| 443 | <tr> |
|---|
| 444 | <td class="left"></td> |
|---|
| 445 | <td class="right">H. Frystyk</td> |
|---|
| 446 | </tr> |
|---|
| 447 | <tr> |
|---|
| 448 | <td class="left"></td> |
|---|
| 449 | <td class="right">Microsoft</td> |
|---|
| 450 | </tr> |
|---|
| 451 | <tr> |
|---|
| 452 | <td class="left"></td> |
|---|
| 453 | <td class="right">L. Masinter</td> |
|---|
| 454 | </tr> |
|---|
| 455 | <tr> |
|---|
| 456 | <td class="left"></td> |
|---|
| 457 | <td class="right">Adobe</td> |
|---|
| 458 | </tr> |
|---|
| 459 | <tr> |
|---|
| 460 | <td class="left"></td> |
|---|
| 461 | <td class="right">P. Leach</td> |
|---|
| 462 | </tr> |
|---|
| 463 | <tr> |
|---|
| 464 | <td class="left"></td> |
|---|
| 465 | <td class="right">Microsoft</td> |
|---|
| 466 | </tr> |
|---|
| 467 | <tr> |
|---|
| 468 | <td class="left"></td> |
|---|
| 469 | <td class="right">T. Berners-Lee</td> |
|---|
| 470 | </tr> |
|---|
| 471 | <tr> |
|---|
| 472 | <td class="left"></td> |
|---|
| 473 | <td class="right">W3C/MIT</td> |
|---|
| 474 | </tr> |
|---|
| 475 | <tr> |
|---|
| 476 | <td class="left"></td> |
|---|
| 477 | <td class="right">Y. Lafon, Editor</td> |
|---|
| 478 | </tr> |
|---|
| 479 | <tr> |
|---|
| 480 | <td class="left"></td> |
|---|
| 481 | <td class="right">W3C</td> |
|---|
| 482 | </tr> |
|---|
| 483 | <tr> |
|---|
| 484 | <td class="left"></td> |
|---|
| 485 | <td class="right">J. Reschke, Editor</td> |
|---|
| 486 | </tr> |
|---|
| 487 | <tr> |
|---|
| 488 | <td class="left"></td> |
|---|
| 489 | <td class="right">greenbytes</td> |
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| 490 | </tr> |
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| 491 | <tr> |
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| 492 | <td class="left"></td> |
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| 493 | <td class="right">October 31, 2011</td> |
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| 494 | </tr> |
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| 495 | </tbody> |
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| 496 | </table> |
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| 497 | <p class="title">HTTP/1.1, part 3: Message Payload and Content Negotiation<br><span class="filename">draft-ietf-httpbis-p3-payload-latest</span></p> |
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| 498 | <h1 id="rfc.abstract"><a href="#rfc.abstract">Abstract</a></h1> |
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| 499 | <p>The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypertext information |
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| 500 | systems. HTTP has been in use by the World Wide Web global information initiative since 1990. This document is Part 3 of the |
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| 501 | seven-part specification that defines the protocol referred to as "HTTP/1.1" and, taken together, obsoletes RFC 2616. |
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| 502 | </p> |
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| 503 | <p>Part 3 defines HTTP message content, metadata, and content negotiation.</p> |
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| 504 | <h1 id="rfc.note.1"><a href="#rfc.note.1">Editorial Note (To be removed by RFC Editor)</a></h1> |
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| 505 | <p>Discussion of this draft should take place on the HTTPBIS working group mailing list (ietf-http-wg@w3.org), which is archived |
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| 506 | at <<a href="http://lists.w3.org/Archives/Public/ietf-http-wg/">http://lists.w3.org/Archives/Public/ietf-http-wg/</a>>. |
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| 507 | </p> |
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| 508 | <p>The current issues list is at <<a href="http://tools.ietf.org/wg/httpbis/trac/report/3">http://tools.ietf.org/wg/httpbis/trac/report/3</a>> and related documents (including fancy diffs) can be found at <<a href="http://tools.ietf.org/wg/httpbis/">http://tools.ietf.org/wg/httpbis/</a>>. |
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| 509 | </p> |
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| 510 | <p>The changes in this draft are summarized in <a href="#changes.since.16" title="Since draft-ietf-httpbis-p3-payload-16">Appendix E.18</a>. |
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| 511 | </p> |
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| 512 | <h1><a id="rfc.status" href="#rfc.status">Status of This Memo</a></h1> |
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| 513 | <p>This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.</p> |
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| 514 | <p>Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute |
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| 515 | working documents as Internet-Drafts. The list of current Internet-Drafts is at <a href="http://datatracker.ietf.org/drafts/current/">http://datatracker.ietf.org/drafts/current/</a>. |
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| 516 | </p> |
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| 517 | <p>Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other |
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| 518 | documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as “work |
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| 519 | in progress”. |
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| 520 | </p> |
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| 521 | <p>This Internet-Draft will expire on May 3, 2012.</p> |
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| 522 | <h1><a id="rfc.copyrightnotice" href="#rfc.copyrightnotice">Copyright Notice</a></h1> |
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| 523 | <p>Copyright © 2011 IETF Trust and the persons identified as the document authors. All rights reserved.</p> |
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| 524 | <p>This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (<a href="http://trustee.ietf.org/license-info">http://trustee.ietf.org/license-info</a>) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights |
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| 525 | and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License |
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| 526 | text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified |
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| 527 | BSD License. |
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| 528 | </p> |
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| 529 | <p>This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November |
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| 530 | 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to |
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| 531 | allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) |
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| 532 | controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative |
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| 533 | works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate |
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| 534 | it into languages other than English. |
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| 535 | </p> |
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| 536 | <hr class="noprint"> |
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| 537 | <h1 class="np" id="rfc.toc"><a href="#rfc.toc">Table of Contents</a></h1> |
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| 538 | <ul class="toc"> |
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| 539 | <li>1. <a href="#introduction">Introduction</a><ul> |
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| 540 | <li>1.1 <a href="#terminology">Terminology</a></li> |
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| 541 | <li>1.2 <a href="#intro.conformance.and.error.handling">Conformance and Error Handling</a></li> |
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| 542 | <li>1.3 <a href="#notation">Syntax Notation</a><ul> |
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| 543 | <li>1.3.1 <a href="#core.rules">Core Rules</a></li> |
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| 544 | <li>1.3.2 <a href="#abnf.dependencies">ABNF Rules defined in other Parts of the Specification</a></li> |
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| 545 | </ul> |
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| 546 | </li> |
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| 547 | </ul> |
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| 548 | </li> |
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| 549 | <li>2. <a href="#protocol.parameters">Protocol Parameters</a><ul> |
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| 550 | <li>2.1 <a href="#character.sets">Character Encodings (charset)</a></li> |
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| 551 | <li>2.2 <a href="#content.codings">Content Codings</a><ul> |
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| 552 | <li>2.2.1 <a href="#content.coding.registry">Content Coding Registry</a></li> |
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| 553 | </ul> |
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| 554 | </li> |
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| 555 | <li>2.3 <a href="#media.types">Media Types</a><ul> |
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| 556 | <li>2.3.1 <a href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></li> |
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| 557 | <li>2.3.2 <a href="#multipart.types">Multipart Types</a></li> |
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| 558 | </ul> |
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| 559 | </li> |
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| 560 | <li>2.4 <a href="#language.tags">Language Tags</a></li> |
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| 561 | </ul> |
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| 562 | </li> |
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| 563 | <li>3. <a href="#payload">Payload</a><ul> |
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| 564 | <li>3.1 <a href="#payload.header.fields">Payload Header Fields</a></li> |
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| 565 | <li>3.2 <a href="#payload.body">Payload Body</a></li> |
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| 566 | </ul> |
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| 567 | </li> |
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| 568 | <li>4. <a href="#representation">Representation</a><ul> |
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| 569 | <li>4.1 <a href="#representation.header.fields">Representation Header Fields</a></li> |
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| 570 | <li>4.2 <a href="#representation.data">Representation Data</a></li> |
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| 571 | </ul> |
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| 572 | </li> |
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| 573 | <li>5. <a href="#content.negotiation">Content Negotiation</a><ul> |
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| 574 | <li>5.1 <a href="#server-driven.negotiation">Server-driven Negotiation</a></li> |
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| 575 | <li>5.2 <a href="#agent-driven.negotiation">Agent-driven Negotiation</a></li> |
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| 576 | </ul> |
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| 577 | </li> |
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| 578 | <li>6. <a href="#header.field.definitions">Header Field Definitions</a><ul> |
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| 579 | <li>6.1 <a href="#header.accept">Accept</a></li> |
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| 580 | <li>6.2 <a href="#header.accept-charset">Accept-Charset</a></li> |
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| 581 | <li>6.3 <a href="#header.accept-encoding">Accept-Encoding</a></li> |
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| 582 | <li>6.4 <a href="#header.accept-language">Accept-Language</a></li> |
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| 583 | <li>6.5 <a href="#header.content-encoding">Content-Encoding</a></li> |
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| 584 | <li>6.6 <a href="#header.content-language">Content-Language</a></li> |
|---|
| 585 | <li>6.7 <a href="#header.content-location">Content-Location</a></li> |
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| 586 | <li>6.8 <a href="#header.content-type">Content-Type</a></li> |
|---|
| 587 | </ul> |
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| 588 | </li> |
|---|
| 589 | <li>7. <a href="#IANA.considerations">IANA Considerations</a><ul> |
|---|
| 590 | <li>7.1 <a href="#header.field.registration">Header Field Registration</a></li> |
|---|
| 591 | <li>7.2 <a href="#content.coding.registration">Content Coding Registry</a></li> |
|---|
| 592 | </ul> |
|---|
| 593 | </li> |
|---|
| 594 | <li>8. <a href="#security.considerations">Security Considerations</a><ul> |
|---|
| 595 | <li>8.1 <a href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></li> |
|---|
| 596 | </ul> |
|---|
| 597 | </li> |
|---|
| 598 | <li>9. <a href="#acks">Acknowledgments</a></li> |
|---|
| 599 | <li>10. <a href="#rfc.references">References</a><ul> |
|---|
| 600 | <li>10.1 <a href="#rfc.references.1">Normative References</a></li> |
|---|
| 601 | <li>10.2 <a href="#rfc.references.2">Informative References</a></li> |
|---|
| 602 | </ul> |
|---|
| 603 | </li> |
|---|
| 604 | <li><a href="#rfc.authors">Authors' Addresses</a></li> |
|---|
| 605 | <li>A. <a href="#differences.between.http.and.mime">Differences between HTTP and MIME</a><ul> |
|---|
| 606 | <li>A.1 <a href="#mime-version">MIME-Version</a></li> |
|---|
| 607 | <li>A.2 <a href="#conversion.to.canonical.form">Conversion to Canonical Form</a></li> |
|---|
| 608 | <li>A.3 <a href="#conversion.of.date.formats">Conversion of Date Formats</a></li> |
|---|
| 609 | <li>A.4 <a href="#introduction.of.content-encoding">Introduction of Content-Encoding</a></li> |
|---|
| 610 | <li>A.5 <a href="#no.content-transfer-encoding">No Content-Transfer-Encoding</a></li> |
|---|
| 611 | <li>A.6 <a href="#introduction.of.transfer-encoding">Introduction of Transfer-Encoding</a></li> |
|---|
| 612 | <li>A.7 <a href="#mhtml.line.length">MHTML and Line Length Limitations</a></li> |
|---|
| 613 | </ul> |
|---|
| 614 | </li> |
|---|
| 615 | <li>B. <a href="#additional.features">Additional Features</a></li> |
|---|
| 616 | <li>C. <a href="#changes.from.rfc.2616">Changes from RFC 2616</a></li> |
|---|
| 617 | <li>D. <a href="#collected.abnf">Collected ABNF</a></li> |
|---|
| 618 | <li>E. <a href="#change.log">Change Log (to be removed by RFC Editor before publication)</a><ul> |
|---|
| 619 | <li>E.1 <a href="#rfc.section.E.1">Since RFC 2616</a></li> |
|---|
| 620 | <li>E.2 <a href="#rfc.section.E.2">Since draft-ietf-httpbis-p3-payload-00</a></li> |
|---|
| 621 | <li>E.3 <a href="#rfc.section.E.3">Since draft-ietf-httpbis-p3-payload-01</a></li> |
|---|
| 622 | <li>E.4 <a href="#changes.since.02">Since draft-ietf-httpbis-p3-payload-02</a></li> |
|---|
| 623 | <li>E.5 <a href="#changes.since.03">Since draft-ietf-httpbis-p3-payload-03</a></li> |
|---|
| 624 | <li>E.6 <a href="#changes.since.04">Since draft-ietf-httpbis-p3-payload-04</a></li> |
|---|
| 625 | <li>E.7 <a href="#changes.since.05">Since draft-ietf-httpbis-p3-payload-05</a></li> |
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| 626 | <li>E.8 <a href="#changes.since.06">Since draft-ietf-httpbis-p3-payload-06</a></li> |
|---|
| 627 | <li>E.9 <a href="#changes.since.07">Since draft-ietf-httpbis-p3-payload-07</a></li> |
|---|
| 628 | <li>E.10 <a href="#changes.since.08">Since draft-ietf-httpbis-p3-payload-08</a></li> |
|---|
| 629 | <li>E.11 <a href="#changes.since.09">Since draft-ietf-httpbis-p3-payload-09</a></li> |
|---|
| 630 | <li>E.12 <a href="#changes.since.10">Since draft-ietf-httpbis-p3-payload-10</a></li> |
|---|
| 631 | <li>E.13 <a href="#changes.since.11">Since draft-ietf-httpbis-p3-payload-11</a></li> |
|---|
| 632 | <li>E.14 <a href="#changes.since.12">Since draft-ietf-httpbis-p3-payload-12</a></li> |
|---|
| 633 | <li>E.15 <a href="#changes.since.13">Since draft-ietf-httpbis-p3-payload-13</a></li> |
|---|
| 634 | <li>E.16 <a href="#changes.since.14">Since draft-ietf-httpbis-p3-payload-14</a></li> |
|---|
| 635 | <li>E.17 <a href="#changes.since.15">Since draft-ietf-httpbis-p3-payload-15</a></li> |
|---|
| 636 | <li>E.18 <a href="#changes.since.16">Since draft-ietf-httpbis-p3-payload-16</a></li> |
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| 637 | </ul> |
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| 638 | </li> |
|---|
| 639 | <li><a href="#rfc.index">Index</a></li> |
|---|
| 640 | </ul> |
|---|
| 641 | <h1 id="rfc.section.1" class="np"><a href="#rfc.section.1">1.</a> <a id="introduction" href="#introduction">Introduction</a></h1> |
|---|
| 642 | <p id="rfc.section.1.p.1">This document defines HTTP/1.1 message payloads (a.k.a., content), the associated metadata header fields that define how the |
|---|
| 643 | payload is intended to be interpreted by a recipient, the request header fields that might influence content selection, and |
|---|
| 644 | the various selection algorithms that are collectively referred to as HTTP content negotiation. |
|---|
| 645 | </p> |
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| 646 | <p id="rfc.section.1.p.2">This document is currently disorganized in order to minimize the changes between drafts and enable reviewers to see the smaller |
|---|
| 647 | errata changes. A future draft will reorganize the sections to better reflect the content. In particular, the sections on |
|---|
| 648 | entities will be renamed payload and moved to the first half of the document, while the sections on content negotiation and |
|---|
| 649 | associated request header fields will be moved to the second half. The current mess reflects how widely dispersed these topics |
|---|
| 650 | and associated requirements had become in <a href="#RFC2616" id="rfc.xref.RFC2616.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>. |
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| 651 | </p> |
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| 652 | <h2 id="rfc.section.1.1"><a href="#rfc.section.1.1">1.1</a> <a id="terminology" href="#terminology">Terminology</a></h2> |
|---|
| 653 | <p id="rfc.section.1.1.p.1">This specification uses a number of terms to refer to the roles played by participants in, and objects of, the HTTP communication.</p> |
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| 654 | <p id="rfc.section.1.1.p.2"> <span id="rfc.iref.c.1"></span> <dfn>content negotiation</dfn> |
|---|
| 655 | </p> |
|---|
| 656 | <ul class="empty"> |
|---|
| 657 | <li>The mechanism for selecting the appropriate representation when servicing a request. The representation in any response can |
|---|
| 658 | be negotiated (including error responses). |
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| 659 | </li> |
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| 660 | </ul> |
|---|
| 661 | <h2 id="rfc.section.1.2"><a href="#rfc.section.1.2">1.2</a> <a id="intro.conformance.and.error.handling" href="#intro.conformance.and.error.handling">Conformance and Error Handling</a></h2> |
|---|
| 662 | <p id="rfc.section.1.2.p.1">The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" |
|---|
| 663 | in this document are to be interpreted as described in <a href="#RFC2119" id="rfc.xref.RFC2119.1"><cite title="Key words for use in RFCs to Indicate Requirement Levels">[RFC2119]</cite></a>. |
|---|
| 664 | </p> |
|---|
| 665 | <p id="rfc.section.1.2.p.2">This document defines conformance criteria for several roles in HTTP communication, including Senders, Recipients, Clients, |
|---|
| 666 | Servers, User-Agents, Origin Servers, Intermediaries, Proxies and Gateways. See <a href="p1-messaging.html#architecture" title="Architecture">Section 2</a> of <a href="#Part1" id="rfc.xref.Part1.1"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a> for definitions of these terms. |
|---|
| 667 | </p> |
|---|
| 668 | <p id="rfc.section.1.2.p.3">An implementation is considered conformant if it complies with all of the requirements associated with its role(s). Note that |
|---|
| 669 | SHOULD-level requirements are relevant here, unless one of the documented exceptions is applicable. |
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| 670 | </p> |
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| 671 | <p id="rfc.section.1.2.p.4">This document also uses ABNF to define valid protocol elements (<a href="#notation" title="Syntax Notation">Section 1.3</a>). In addition to the prose requirements placed upon them, Senders <em class="bcp14">MUST NOT</em> generate protocol elements that are invalid. |
|---|
| 672 | </p> |
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| 673 | <p id="rfc.section.1.2.p.5">Unless noted otherwise, Recipients <em class="bcp14">MAY</em> take steps to recover a usable protocol element from an invalid construct. However, HTTP does not define specific error handling |
|---|
| 674 | mechanisms, except in cases where it has direct impact on security. This is because different uses of the protocol require |
|---|
| 675 | different error handling strategies; for example, a Web browser may wish to transparently recover from a response where the |
|---|
| 676 | Location header field doesn't parse according to the ABNF, whereby in a systems control protocol using HTTP, this type of |
|---|
| 677 | error recovery could lead to dangerous consequences. |
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| 678 | </p> |
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| 679 | <h2 id="rfc.section.1.3"><a href="#rfc.section.1.3">1.3</a> <a id="notation" href="#notation">Syntax Notation</a></h2> |
|---|
| 680 | <p id="rfc.section.1.3.p.1">This specification uses the ABNF syntax defined in <a href="p1-messaging.html#notation" title="Syntax Notation">Section 1.2</a> of <a href="#Part1" id="rfc.xref.Part1.2"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a> (which extends the syntax defined in <a href="#RFC5234" id="rfc.xref.RFC5234.1"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a> with a list rule). <a href="#collected.abnf" title="Collected ABNF">Appendix D</a> shows the collected ABNF, with the list rule expanded. |
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| 681 | </p> |
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| 682 | <p id="rfc.section.1.3.p.2">The following core rules are included by reference, as defined in <a href="#RFC5234" id="rfc.xref.RFC5234.2"><cite title="Augmented BNF for Syntax Specifications: ABNF">[RFC5234]</cite></a>, <a href="http://tools.ietf.org/html/rfc5234#appendix-B.1">Appendix B.1</a>: ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls), DIGIT (decimal 0-9), DQUOTE (double quote), HEXDIG |
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| 683 | (hexadecimal 0-9/A-F/a-f), LF (line feed), OCTET (any 8-bit sequence of data), SP (space), and VCHAR (any visible US-ASCII |
|---|
| 684 | character). |
|---|
| 685 | </p> |
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| 686 | <h3 id="rfc.section.1.3.1"><a href="#rfc.section.1.3.1">1.3.1</a> <a id="core.rules" href="#core.rules">Core Rules</a></h3> |
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| 687 | <p id="rfc.section.1.3.1.p.1">The core rules below are defined in <a href="#Part1" id="rfc.xref.Part1.3"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>: |
|---|
| 688 | </p> |
|---|
| 689 | <div id="rfc.figure.u.1"></div><pre class="inline"> <a href="#core.rules" class="smpl">OWS</a> = <OWS, defined in <a href="#Part1" id="rfc.xref.Part1.4"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#basic.rules" title="Basic Rules">Section 1.2.2</a>> |
|---|
| 690 | <a href="#core.rules" class="smpl">token</a> = <token, defined in <a href="#Part1" id="rfc.xref.Part1.5"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#field.rules" title="Common Field ABNF Rules">Section 3.2.3</a>> |
|---|
| 691 | <a href="#core.rules" class="smpl">word</a> = <word, defined in <a href="#Part1" id="rfc.xref.Part1.6"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#field.rules" title="Common Field ABNF Rules">Section 3.2.3</a>> |
|---|
| 692 | </pre><h3 id="rfc.section.1.3.2"><a href="#rfc.section.1.3.2">1.3.2</a> <a id="abnf.dependencies" href="#abnf.dependencies">ABNF Rules defined in other Parts of the Specification</a></h3> |
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| 693 | <p id="rfc.section.1.3.2.p.1">The ABNF rules below are defined in other parts:</p> |
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| 694 | <div id="rfc.figure.u.2"></div><pre class="inline"> <a href="#abnf.dependencies" class="smpl">absolute-URI</a> = <absolute-URI, defined in <a href="#Part1" id="rfc.xref.Part1.7"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#uri" title="Uniform Resource Identifiers">Section 2.7</a>> |
|---|
| 695 | <a href="#abnf.dependencies" class="smpl">partial-URI</a> = <partial-URI, defined in <a href="#Part1" id="rfc.xref.Part1.8"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#uri" title="Uniform Resource Identifiers">Section 2.7</a>> |
|---|
| 696 | <a href="#abnf.dependencies" class="smpl">qvalue</a> = <qvalue, defined in <a href="#Part1" id="rfc.xref.Part1.9"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, <a href="p1-messaging.html#quality.values" title="Quality Values">Section 5.3</a>> |
|---|
| 697 | </pre><h1 id="rfc.section.2"><a href="#rfc.section.2">2.</a> <a id="protocol.parameters" href="#protocol.parameters">Protocol Parameters</a></h1> |
|---|
| 698 | <h2 id="rfc.section.2.1"><a href="#rfc.section.2.1">2.1</a> <a id="character.sets" href="#character.sets">Character Encodings (charset)</a></h2> |
|---|
| 699 | <p id="rfc.section.2.1.p.1">HTTP uses charset names to indicate the character encoding of a textual representation.</p> |
|---|
| 700 | <div id="rule.charset"> |
|---|
| 701 | <p id="rfc.section.2.1.p.2"> A character encoding is identified by a case-insensitive token. The complete set of tokens is defined by the IANA Character |
|---|
| 702 | Set registry (<<a href="http://www.iana.org/assignments/character-sets">http://www.iana.org/assignments/character-sets</a>>). |
|---|
| 703 | </p> |
|---|
| 704 | </div> |
|---|
| 705 | <div id="rfc.figure.u.3"></div><pre class="inline"><span id="rfc.iref.g.1"></span> <a href="#rule.charset" class="smpl">charset</a> = <a href="#core.rules" class="smpl">token</a> |
|---|
| 706 | </pre><p id="rfc.section.2.1.p.4">Although HTTP allows an arbitrary token to be used as a charset value, any token that has a predefined value within the IANA |
|---|
| 707 | Character Set registry <em class="bcp14">MUST</em> represent the character encoding defined by that registry. Applications <em class="bcp14">SHOULD</em> limit their use of character encodings to those defined within the IANA registry. |
|---|
| 708 | </p> |
|---|
| 709 | <p id="rfc.section.2.1.p.5">HTTP uses charset in two contexts: within an Accept-Charset request header field (in which the charset value is an unquoted |
|---|
| 710 | token) and as the value of a parameter in a Content-Type header field (within a request or response), in which case the parameter |
|---|
| 711 | value of the charset parameter can be quoted. |
|---|
| 712 | </p> |
|---|
| 713 | <p id="rfc.section.2.1.p.6">Implementors need to be aware of IETF character set requirements <a href="#RFC3629" id="rfc.xref.RFC3629.1"><cite title="UTF-8, a transformation format of ISO 10646">[RFC3629]</cite></a> <a href="#RFC2277" id="rfc.xref.RFC2277.1"><cite title="IETF Policy on Character Sets and Languages">[RFC2277]</cite></a>. |
|---|
| 714 | </p> |
|---|
| 715 | <h2 id="rfc.section.2.2"><a href="#rfc.section.2.2">2.2</a> <a id="content.codings" href="#content.codings">Content Codings</a></h2> |
|---|
| 716 | <p id="rfc.section.2.2.p.1">Content coding values indicate an encoding transformation that has been or can be applied to a representation. Content codings |
|---|
| 717 | are primarily used to allow a representation to be compressed or otherwise usefully transformed without losing the identity |
|---|
| 718 | of its underlying media type and without loss of information. Frequently, the representation is stored in coded form, transmitted |
|---|
| 719 | directly, and only decoded by the recipient. |
|---|
| 720 | </p> |
|---|
| 721 | <div id="rfc.figure.u.4"></div><pre class="inline"><span id="rfc.iref.g.2"></span> <a href="#content.codings" class="smpl">content-coding</a> = <a href="#core.rules" class="smpl">token</a> |
|---|
| 722 | </pre><p id="rfc.section.2.2.p.3">All content-coding values are case-insensitive. HTTP/1.1 uses content-coding values in the Accept-Encoding (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.1" title="Accept-Encoding">Section 6.3</a>) and Content-Encoding (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.1" title="Content-Encoding">Section 6.5</a>) header fields. Although the value describes the content-coding, what is more important is that it indicates what decoding |
|---|
| 723 | mechanism will be required to remove the encoding. |
|---|
| 724 | </p> |
|---|
| 725 | <p id="rfc.section.2.2.p.4">compress<span id="rfc.iref.c.2"></span><span id="rfc.iref.c.3"></span> |
|---|
| 726 | </p> |
|---|
| 727 | <ul class="empty"> |
|---|
| 728 | <li>See <a href="p1-messaging.html#compress.coding" title="Compress Coding">Section 5.1.2.1</a> of <a href="#Part1" id="rfc.xref.Part1.10"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. |
|---|
| 729 | </li> |
|---|
| 730 | </ul> |
|---|
| 731 | <p id="rfc.section.2.2.p.5">deflate<span id="rfc.iref.d.1"></span><span id="rfc.iref.c.4"></span> |
|---|
| 732 | </p> |
|---|
| 733 | <ul class="empty"> |
|---|
| 734 | <li>See <a href="p1-messaging.html#deflate.coding" title="Deflate Coding">Section 5.1.2.2</a> of <a href="#Part1" id="rfc.xref.Part1.11"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. |
|---|
| 735 | </li> |
|---|
| 736 | </ul> |
|---|
| 737 | <p id="rfc.section.2.2.p.6">gzip<span id="rfc.iref.g.3"></span><span id="rfc.iref.c.5"></span> |
|---|
| 738 | </p> |
|---|
| 739 | <ul class="empty"> |
|---|
| 740 | <li>See <a href="p1-messaging.html#gzip.coding" title="Gzip Coding">Section 5.1.2.3</a> of <a href="#Part1" id="rfc.xref.Part1.12"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. |
|---|
| 741 | </li> |
|---|
| 742 | </ul> |
|---|
| 743 | <h3 id="rfc.section.2.2.1"><a href="#rfc.section.2.2.1">2.2.1</a> <a id="content.coding.registry" href="#content.coding.registry">Content Coding Registry</a></h3> |
|---|
| 744 | <p id="rfc.section.2.2.1.p.1">The HTTP Content Coding Registry defines the name space for the content coding names.</p> |
|---|
| 745 | <p id="rfc.section.2.2.1.p.2">Registrations <em class="bcp14">MUST</em> include the following fields: |
|---|
| 746 | </p> |
|---|
| 747 | <ul> |
|---|
| 748 | <li>Name</li> |
|---|
| 749 | <li>Description</li> |
|---|
| 750 | <li>Pointer to specification text</li> |
|---|
| 751 | </ul> |
|---|
| 752 | <p id="rfc.section.2.2.1.p.3">Names of content codings <em class="bcp14">MUST NOT</em> overlap with names of transfer codings (<a href="p1-messaging.html#transfer.codings" title="Transfer Codings">Section 5.1</a> of <a href="#Part1" id="rfc.xref.Part1.13"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>), unless the encoding transformation is identical (as it is the case for the compression codings defined in <a href="p1-messaging.html#compression.codings" title="Compression Codings">Section 5.1.2</a> of <a href="#Part1" id="rfc.xref.Part1.14"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>). |
|---|
| 753 | </p> |
|---|
| 754 | <p id="rfc.section.2.2.1.p.4">Values to be added to this name space require a specification (see "Specification Required" in <a href="http://tools.ietf.org/html/rfc5226#section-4.1">Section 4.1</a> of <a href="#RFC5226" id="rfc.xref.RFC5226.1"><cite title="Guidelines for Writing an IANA Considerations Section in RFCs">[RFC5226]</cite></a>), and <em class="bcp14">MUST</em> conform to the purpose of content coding defined in this section. |
|---|
| 755 | </p> |
|---|
| 756 | <p id="rfc.section.2.2.1.p.5">The registry itself is maintained at <<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>>. |
|---|
| 757 | </p> |
|---|
| 758 | <h2 id="rfc.section.2.3"><a href="#rfc.section.2.3">2.3</a> <a id="media.types" href="#media.types">Media Types</a></h2> |
|---|
| 759 | <p id="rfc.section.2.3.p.1">HTTP uses Internet Media Types <a href="#RFC2046" id="rfc.xref.RFC2046.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> in the Content-Type (<a href="#header.content-type" id="rfc.xref.header.content-type.1" title="Content-Type">Section 6.8</a>) and Accept (<a href="#header.accept" id="rfc.xref.header.accept.1" title="Accept">Section 6.1</a>) header fields in order to provide open and extensible data typing and type negotiation. |
|---|
| 760 | </p> |
|---|
| 761 | <div id="rfc.figure.u.5"></div><pre class="inline"><span id="rfc.iref.g.4"></span><span id="rfc.iref.g.5"></span><span id="rfc.iref.g.6"></span> <a href="#media.types" class="smpl">media-type</a> = <a href="#media.types" class="smpl">type</a> "/" <a href="#media.types" class="smpl">subtype</a> *( <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> ) |
|---|
| 762 | <a href="#media.types" class="smpl">type</a> = <a href="#core.rules" class="smpl">token</a> |
|---|
| 763 | <a href="#media.types" class="smpl">subtype</a> = <a href="#core.rules" class="smpl">token</a> |
|---|
| 764 | </pre><div id="rule.parameter"> |
|---|
| 765 | <p id="rfc.section.2.3.p.3"> The type/subtype <em class="bcp14">MAY</em> be followed by parameters in the form of attribute/value pairs. |
|---|
| 766 | </p> |
|---|
| 767 | </div> |
|---|
| 768 | <div id="rfc.figure.u.6"></div><pre class="inline"><span id="rfc.iref.g.7"></span><span id="rfc.iref.g.8"></span><span id="rfc.iref.g.9"></span> <a href="#rule.parameter" class="smpl">parameter</a> = <a href="#rule.parameter" class="smpl">attribute</a> "=" <a href="#rule.parameter" class="smpl">value</a> |
|---|
| 769 | <a href="#rule.parameter" class="smpl">attribute</a> = <a href="#core.rules" class="smpl">token</a> |
|---|
| 770 | <a href="#rule.parameter" class="smpl">value</a> = <a href="#core.rules" class="smpl">word</a> |
|---|
| 771 | </pre><p id="rfc.section.2.3.p.5">The type, subtype, and parameter attribute names are case-insensitive. Parameter values might or might not be case-sensitive, |
|---|
| 772 | depending on the semantics of the parameter name. The presence or absence of a parameter might be significant to the processing |
|---|
| 773 | of a media-type, depending on its definition within the media type registry. |
|---|
| 774 | </p> |
|---|
| 775 | <p id="rfc.section.2.3.p.6">A parameter value that matches the <a href="#core.rules" class="smpl">token</a> production can be transmitted as either a token or within a quoted-string. The quoted and unquoted values are equivalent. |
|---|
| 776 | </p> |
|---|
| 777 | <p id="rfc.section.2.3.p.7">Note that some older HTTP applications do not recognize media type parameters. When sending data to older HTTP applications, |
|---|
| 778 | implementations <em class="bcp14">SHOULD</em> only use media type parameters when they are required by that type/subtype definition. |
|---|
| 779 | </p> |
|---|
| 780 | <p id="rfc.section.2.3.p.8">Media-type values are registered with the Internet Assigned Number Authority (IANA). The media type registration process is |
|---|
| 781 | outlined in <a href="#RFC4288" id="rfc.xref.RFC4288.1"><cite title="Media Type Specifications and Registration Procedures">[RFC4288]</cite></a>. Use of non-registered media types is discouraged. |
|---|
| 782 | </p> |
|---|
| 783 | <h3 id="rfc.section.2.3.1"><a href="#rfc.section.2.3.1">2.3.1</a> <a id="canonicalization.and.text.defaults" href="#canonicalization.and.text.defaults">Canonicalization and Text Defaults</a></h3> |
|---|
| 784 | <p id="rfc.section.2.3.1.p.1">Internet media types are registered with a canonical form. A representation transferred via HTTP messages <em class="bcp14">MUST</em> be in the appropriate canonical form prior to its transmission except for "text" types, as defined in the next paragraph. |
|---|
| 785 | </p> |
|---|
| 786 | <p id="rfc.section.2.3.1.p.2">When in canonical form, media subtypes of the "text" type use CRLF as the text line break. HTTP relaxes this requirement and |
|---|
| 787 | allows the transport of text media with plain CR or LF alone representing a line break when it is done consistently for an |
|---|
| 788 | entire representation. HTTP applications <em class="bcp14">MUST</em> accept CRLF, bare CR, and bare LF as indicating a line break in text media received via HTTP. In addition, if the text is |
|---|
| 789 | in a character encoding that does not use octets 13 and 10 for CR and LF respectively, as is the case for some multi-byte |
|---|
| 790 | character encodings, HTTP allows the use of whatever octet sequences are defined by that character encoding to represent the |
|---|
| 791 | equivalent of CR and LF for line breaks. This flexibility regarding line breaks applies only to text media in the payload |
|---|
| 792 | body; a bare CR or LF <em class="bcp14">MUST NOT</em> be substituted for CRLF within any of the HTTP control structures (such as header fields and multipart boundaries). |
|---|
| 793 | </p> |
|---|
| 794 | <p id="rfc.section.2.3.1.p.3">If a representation is encoded with a content-coding, the underlying data <em class="bcp14">MUST</em> be in a form defined above prior to being encoded. |
|---|
| 795 | </p> |
|---|
| 796 | <h3 id="rfc.section.2.3.2"><a href="#rfc.section.2.3.2">2.3.2</a> <a id="multipart.types" href="#multipart.types">Multipart Types</a></h3> |
|---|
| 797 | <p id="rfc.section.2.3.2.p.1">MIME provides for a number of "multipart" types — encapsulations of one or more representations within a single message-body. |
|---|
| 798 | All multipart types share a common syntax, as defined in <a href="http://tools.ietf.org/html/rfc2046#section-5.1.1">Section 5.1.1</a> of <a href="#RFC2046" id="rfc.xref.RFC2046.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, and <em class="bcp14">MUST</em> include a boundary parameter as part of the media type value. The message body is itself a protocol element and <em class="bcp14">MUST</em> therefore use only CRLF to represent line breaks between body-parts. |
|---|
| 799 | </p> |
|---|
| 800 | <p id="rfc.section.2.3.2.p.2">In general, HTTP treats a multipart message-body no differently than any other media type: strictly as payload. HTTP does |
|---|
| 801 | not use the multipart boundary as an indicator of message-body length. In all other respects, an HTTP user agent <em class="bcp14">SHOULD</em> follow the same or similar behavior as a MIME user agent would upon receipt of a multipart type. The MIME header fields within |
|---|
| 802 | each body-part of a multipart message-body do not have any significance to HTTP beyond that defined by their MIME semantics. |
|---|
| 803 | </p> |
|---|
| 804 | <p id="rfc.section.2.3.2.p.3">If an application receives an unrecognized multipart subtype, the application <em class="bcp14">MUST</em> treat it as being equivalent to "multipart/mixed". |
|---|
| 805 | </p> |
|---|
| 806 | <div class="note" id="rfc.section.2.3.2.p.4"> |
|---|
| 807 | <p> <b>Note:</b> The "multipart/form-data" type has been specifically defined for carrying form data suitable for processing via the POST request |
|---|
| 808 | method, as described in <a href="#RFC2388" id="rfc.xref.RFC2388.1"><cite title="Returning Values from Forms: multipart/form-data">[RFC2388]</cite></a>. |
|---|
| 809 | </p> |
|---|
| 810 | </div> |
|---|
| 811 | <h2 id="rfc.section.2.4"><a href="#rfc.section.2.4">2.4</a> <a id="language.tags" href="#language.tags">Language Tags</a></h2> |
|---|
| 812 | <p id="rfc.section.2.4.p.1">A language tag, as defined in <a href="#RFC5646" id="rfc.xref.RFC5646.1"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, identifies a natural language spoken, written, or otherwise conveyed by human beings for communication of information to |
|---|
| 813 | other human beings. Computer languages are explicitly excluded. HTTP uses language tags within the Accept-Language and Content-Language |
|---|
| 814 | fields. |
|---|
| 815 | </p> |
|---|
| 816 | <p id="rfc.section.2.4.p.2">In summary, a language tag is composed of one or more parts: A primary language subtag followed by a possibly empty series |
|---|
| 817 | of subtags: |
|---|
| 818 | </p> |
|---|
| 819 | <div id="rfc.figure.u.7"></div><pre class="inline"><span id="rfc.iref.g.10"></span> <a href="#language.tags" class="smpl">language-tag</a> = <Language-Tag, defined in <a href="#RFC5646" id="rfc.xref.RFC5646.2"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a>, <a href="http://tools.ietf.org/html/rfc5646#section-2.1">Section 2.1</a>> |
|---|
| 820 | </pre><p id="rfc.section.2.4.p.4">White space is not allowed within the tag and all tags are case-insensitive. The name space of language subtags is administered |
|---|
| 821 | by the IANA (see <<a href="http://www.iana.org/assignments/language-subtag-registry">http://www.iana.org/assignments/language-subtag-registry</a>>). |
|---|
| 822 | </p> |
|---|
| 823 | <div id="rfc.figure.u.8"></div> |
|---|
| 824 | <p>Example tags include:</p> <pre class="text"> en, en-US, es-419, az-Arab, x-pig-latin, man-Nkoo-GN |
|---|
| 825 | </pre> <p id="rfc.section.2.4.p.6">See <a href="#RFC5646" id="rfc.xref.RFC5646.3"><cite title="Tags for Identifying Languages">[RFC5646]</cite></a> for further information. |
|---|
| 826 | </p> |
|---|
| 827 | <h1 id="rfc.section.3"><a href="#rfc.section.3">3.</a> <a id="payload" href="#payload">Payload</a></h1> |
|---|
| 828 | <p id="rfc.section.3.p.1">HTTP messages <em class="bcp14">MAY</em> transfer a payload if not otherwise restricted by the request method or response status code. The payload consists of metadata, |
|---|
| 829 | in the form of header fields, and data, in the form of the sequence of octets in the message-body after any transfer-coding |
|---|
| 830 | has been decoded. |
|---|
| 831 | </p> |
|---|
| 832 | <div id="rfc.iref.p.1"></div> |
|---|
| 833 | <p id="rfc.section.3.p.2">A "<dfn>payload</dfn>" in HTTP is always a partial or complete representation of some resource. We use separate terms for payload and representation |
|---|
| 834 | because some messages contain only the associated representation's header fields (e.g., responses to HEAD) or only some part(s) |
|---|
| 835 | of the representation (e.g., the 206 status code). |
|---|
| 836 | </p> |
|---|
| 837 | <h2 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1</a> <a id="payload.header.fields" href="#payload.header.fields">Payload Header Fields</a></h2> |
|---|
| 838 | <p id="rfc.section.3.1.p.1">HTTP header fields that specifically define the payload, rather than the associated representation, are referred to as "payload |
|---|
| 839 | header fields". The following payload header fields are defined by HTTP/1.1: |
|---|
| 840 | </p> |
|---|
| 841 | <div id="rfc.table.u.1"> |
|---|
| 842 | <table class="tt full left" cellpadding="3" cellspacing="0"> |
|---|
| 843 | <thead> |
|---|
| 844 | <tr> |
|---|
| 845 | <th>Header Field Name</th> |
|---|
| 846 | <th>Defined in...</th> |
|---|
| 847 | </tr> |
|---|
| 848 | </thead> |
|---|
| 849 | <tbody> |
|---|
| 850 | <tr> |
|---|
| 851 | <td class="left">Content-Length</td> |
|---|
| 852 | <td class="left"><a href="p1-messaging.html#header.content-length" title="Content-Length">Section 8.2</a> of <a href="#Part1" id="rfc.xref.Part1.15"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a></td> |
|---|
| 853 | </tr> |
|---|
| 854 | <tr> |
|---|
| 855 | <td class="left">Content-Range</td> |
|---|
| 856 | <td class="left"><a href="p5-range.html#header.content-range" title="Content-Range">Section 5.2</a> of <a href="#Part5" id="rfc.xref.Part5.1"><cite title="HTTP/1.1, part 5: Range Requests and Partial Responses">[Part5]</cite></a></td> |
|---|
| 857 | </tr> |
|---|
| 858 | </tbody> |
|---|
| 859 | </table> |
|---|
| 860 | </div> |
|---|
| 861 | <h2 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2</a> <a id="payload.body" href="#payload.body">Payload Body</a></h2> |
|---|
| 862 | <p id="rfc.section.3.2.p.1">A payload body is only present in a message when a message-body is present, as described in <a href="p1-messaging.html#message.body" title="Message Body">Section 3.3</a> of <a href="#Part1" id="rfc.xref.Part1.16"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. The payload body is obtained from the message-body by decoding any Transfer-Encoding that might have been applied to ensure |
|---|
| 863 | safe and proper transfer of the message. |
|---|
| 864 | </p> |
|---|
| 865 | <div id="rfc.iref.r.1"></div> |
|---|
| 866 | <h1 id="rfc.section.4"><a href="#rfc.section.4">4.</a> <a id="representation" href="#representation">Representation</a></h1> |
|---|
| 867 | <p id="rfc.section.4.p.1">A "<dfn>representation</dfn>" is information in a format that can be readily communicated from one party to another. A resource representation is information |
|---|
| 868 | that reflects the state of that resource, as observed at some point in the past (e.g., in a response to GET) or to be desired |
|---|
| 869 | at some point in the future (e.g., in a PUT request). |
|---|
| 870 | </p> |
|---|
| 871 | <p id="rfc.section.4.p.2">Most, but not all, representations transferred via HTTP are intended to be a representation of the target resource (the resource |
|---|
| 872 | identified by the effective request URI). The precise semantics of a representation are determined by the type of message |
|---|
| 873 | (request or response), the request method, the response status code, and the representation metadata. For example, the above |
|---|
| 874 | semantic is true for the representation in any 200 (OK) response to GET and for the representation in any PUT request. A 200 |
|---|
| 875 | response to PUT, in contrast, contains either a representation that describes the successful action or a representation of |
|---|
| 876 | the target resource, with the latter indicated by a Content-Location header field with the same value as the effective request |
|---|
| 877 | URI. Likewise, response messages with an error status code usually contain a representation that describes the error and what |
|---|
| 878 | next steps are suggested for resolving it. |
|---|
| 879 | </p> |
|---|
| 880 | <h2 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1</a> <a id="representation.header.fields" href="#representation.header.fields">Representation Header Fields</a></h2> |
|---|
| 881 | <p id="rfc.section.4.1.p.1">Representation header fields define metadata about the representation data enclosed in the message-body or, if no message-body |
|---|
| 882 | is present, about the representation that would have been transferred in a 200 response to a simultaneous GET request with |
|---|
| 883 | the same effective request URI. |
|---|
| 884 | </p> |
|---|
| 885 | <p id="rfc.section.4.1.p.2">The following header fields are defined as representation metadata:</p> |
|---|
| 886 | <div id="rfc.table.u.2"> |
|---|
| 887 | <table class="tt full left" cellpadding="3" cellspacing="0"> |
|---|
| 888 | <thead> |
|---|
| 889 | <tr> |
|---|
| 890 | <th>Header Field Name</th> |
|---|
| 891 | <th>Defined in...</th> |
|---|
| 892 | </tr> |
|---|
| 893 | </thead> |
|---|
| 894 | <tbody> |
|---|
| 895 | <tr> |
|---|
| 896 | <td class="left">Content-Encoding</td> |
|---|
| 897 | <td class="left"><a href="#header.content-encoding" id="rfc.xref.header.content-encoding.2" title="Content-Encoding">Section 6.5</a></td> |
|---|
| 898 | </tr> |
|---|
| 899 | <tr> |
|---|
| 900 | <td class="left">Content-Language</td> |
|---|
| 901 | <td class="left"><a href="#header.content-language" id="rfc.xref.header.content-language.1" title="Content-Language">Section 6.6</a></td> |
|---|
| 902 | </tr> |
|---|
| 903 | <tr> |
|---|
| 904 | <td class="left">Content-Location</td> |
|---|
| 905 | <td class="left"><a href="#header.content-location" id="rfc.xref.header.content-location.1" title="Content-Location">Section 6.7</a></td> |
|---|
| 906 | </tr> |
|---|
| 907 | <tr> |
|---|
| 908 | <td class="left">Content-Type</td> |
|---|
| 909 | <td class="left"><a href="#header.content-type" id="rfc.xref.header.content-type.2" title="Content-Type">Section 6.8</a></td> |
|---|
| 910 | </tr> |
|---|
| 911 | <tr> |
|---|
| 912 | <td class="left">Expires</td> |
|---|
| 913 | <td class="left"><a href="p6-cache.html#header.expires" title="Expires">Section 3.3</a> of <a href="#Part6" id="rfc.xref.Part6.1"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a></td> |
|---|
| 914 | </tr> |
|---|
| 915 | <tr> |
|---|
| 916 | <td class="left">Last-Modified</td> |
|---|
| 917 | <td class="left"><a href="p4-conditional.html#header.last-modified" title="Last-Modified">Section 2.2</a> of <a href="#Part4" id="rfc.xref.Part4.1"><cite title="HTTP/1.1, part 4: Conditional Requests">[Part4]</cite></a></td> |
|---|
| 918 | </tr> |
|---|
| 919 | </tbody> |
|---|
| 920 | </table> |
|---|
| 921 | </div> |
|---|
| 922 | <h2 id="rfc.section.4.2"><a href="#rfc.section.4.2">4.2</a> <a id="representation.data" href="#representation.data">Representation Data</a></h2> |
|---|
| 923 | <p id="rfc.section.4.2.p.1">The representation body associated with an HTTP message is either provided as the payload body of the message or referred |
|---|
| 924 | to by the message semantics and the effective request URI. The representation data is in a format and encoding defined by |
|---|
| 925 | the representation metadata header fields. |
|---|
| 926 | </p> |
|---|
| 927 | <p id="rfc.section.4.2.p.2">The data type of the representation data is determined via the header fields Content-Type and Content-Encoding. These define |
|---|
| 928 | a two-layer, ordered encoding model: |
|---|
| 929 | </p> |
|---|
| 930 | <div id="rfc.figure.u.9"></div><pre class="text"> representation-data := Content-Encoding( Content-Type( bits ) ) |
|---|
| 931 | </pre><p id="rfc.section.4.2.p.4">Content-Type specifies the media type of the underlying data, which defines both the data format and how that data <em class="bcp14">SHOULD</em> be processed by the recipient (within the scope of the request method semantics). Any HTTP/1.1 message containing a payload |
|---|
| 932 | body <em class="bcp14">SHOULD</em> include a Content-Type header field defining the media type of the associated representation unless that metadata is unknown |
|---|
| 933 | to the sender. If the Content-Type header field is not present, it indicates that the sender does not know the media type |
|---|
| 934 | of the representation; recipients <em class="bcp14">MAY</em> either assume that the media type is "application/octet-stream" (<a href="#RFC2046" id="rfc.xref.RFC2046.3"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a>, <a href="http://tools.ietf.org/html/rfc2046#section-4.5.1">Section 4.5.1</a>) or examine the content to determine its type. |
|---|
| 935 | </p> |
|---|
| 936 | <p id="rfc.section.4.2.p.5">In practice, resource owners do not always properly configure their origin server to provide the correct Content-Type for |
|---|
| 937 | a given representation, with the result that some clients will examine a response body's content and override the specified |
|---|
| 938 | type. Clients that do so risk drawing incorrect conclusions, which might expose additional security risks (e.g., "privilege |
|---|
| 939 | escalation"). Furthermore, it is impossible to determine the sender's intent by examining the data format: many data formats |
|---|
| 940 | match multiple media types that differ only in processing semantics. Implementers are encouraged to provide a means of disabling |
|---|
| 941 | such "content sniffing" when it is used. |
|---|
| 942 | </p> |
|---|
| 943 | <p id="rfc.section.4.2.p.6">Content-Encoding is used to indicate any additional content codings applied to the data, usually for the purpose of data compression, |
|---|
| 944 | that are a property of the representation. If Content-Encoding is not present, then there is no additional encoding beyond |
|---|
| 945 | that defined by the Content-Type. |
|---|
| 946 | </p> |
|---|
| 947 | <h1 id="rfc.section.5"><a href="#rfc.section.5">5.</a> <a id="content.negotiation" href="#content.negotiation">Content Negotiation</a></h1> |
|---|
| 948 | <p id="rfc.section.5.p.1">HTTP responses include a representation which contains information for interpretation, whether by a human user or for further |
|---|
| 949 | processing. Often, the server has different ways of representing the same information; for example, in different formats, |
|---|
| 950 | languages, or using different character encodings. |
|---|
| 951 | </p> |
|---|
| 952 | <p id="rfc.section.5.p.2">HTTP clients and their users might have different or variable capabilities, characteristics or preferences which would influence |
|---|
| 953 | which representation, among those available from the server, would be best for the server to deliver. For this reason, HTTP |
|---|
| 954 | provides mechanisms for "content negotiation" — a process of allowing selection of a representation of a given resource, when |
|---|
| 955 | more than one is available. |
|---|
| 956 | </p> |
|---|
| 957 | <p id="rfc.section.5.p.3">This specification defines two patterns of content negotiation; "server-driven", where the server selects the representation |
|---|
| 958 | based upon the client's stated preferences, and "agent-driven" negotiation, where the server provides a list of representations |
|---|
| 959 | for the client to choose from, based upon their metadata. In addition, there are other patterns: some applications use an |
|---|
| 960 | "active content" pattern, where the server returns active content which runs on the client and, based on client available |
|---|
| 961 | parameters, selects additional resources to invoke. "Transparent Content Negotiation" (<a href="#RFC2295" id="rfc.xref.RFC2295.1"><cite title="Transparent Content Negotiation in HTTP">[RFC2295]</cite></a>) has also been proposed. |
|---|
| 962 | </p> |
|---|
| 963 | <p id="rfc.section.5.p.4">These patterns are all widely used, and have trade-offs in applicability and practicality. In particular, when the number |
|---|
| 964 | of preferences or capabilities to be expressed by a client are large (such as when many different formats are supported by |
|---|
| 965 | a user-agent), server-driven negotiation becomes unwieldy, and might not be appropriate. Conversely, when the number of representations |
|---|
| 966 | to choose from is very large, agent-driven negotiation might not be appropriate. |
|---|
| 967 | </p> |
|---|
| 968 | <p id="rfc.section.5.p.5">Note that in all cases, the supplier of representations has the responsibility for determining which representations might |
|---|
| 969 | be considered to be the "same information". |
|---|
| 970 | </p> |
|---|
| 971 | <h2 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1</a> <a id="server-driven.negotiation" href="#server-driven.negotiation">Server-driven Negotiation</a></h2> |
|---|
| 972 | <p id="rfc.section.5.1.p.1">If the selection of the best representation for a response is made by an algorithm located at the server, it is called server-driven |
|---|
| 973 | negotiation. Selection is based on the available representations of the response (the dimensions over which it can vary; e.g., |
|---|
| 974 | language, content-coding, etc.) and the contents of particular header fields in the request message or on other information |
|---|
| 975 | pertaining to the request (such as the network address of the client). |
|---|
| 976 | </p> |
|---|
| 977 | <p id="rfc.section.5.1.p.2">Server-driven negotiation is advantageous when the algorithm for selecting from among the available representations is difficult |
|---|
| 978 | to describe to the user agent, or when the server desires to send its "best guess" to the client along with the first response |
|---|
| 979 | (hoping to avoid the round-trip delay of a subsequent request if the "best guess" is good enough for the user). In order to |
|---|
| 980 | improve the server's guess, the user agent <em class="bcp14">MAY</em> include request header fields (Accept, Accept-Language, Accept-Encoding, etc.) which describe its preferences for such a response. |
|---|
| 981 | </p> |
|---|
| 982 | <p id="rfc.section.5.1.p.3">Server-driven negotiation has disadvantages: </p> |
|---|
| 983 | <ol> |
|---|
| 984 | <li>It is impossible for the server to accurately determine what might be "best" for any given user, since that would require |
|---|
| 985 | complete knowledge of both the capabilities of the user agent and the intended use for the response (e.g., does the user want |
|---|
| 986 | to view it on screen or print it on paper?). |
|---|
| 987 | </li> |
|---|
| 988 | <li>Having the user agent describe its capabilities in every request can be both very inefficient (given that only a small percentage |
|---|
| 989 | of responses have multiple representations) and a potential violation of the user's privacy. |
|---|
| 990 | </li> |
|---|
| 991 | <li>It complicates the implementation of an origin server and the algorithms for generating responses to a request.</li> |
|---|
| 992 | <li>It might limit a public cache's ability to use the same response for multiple user's requests.</li> |
|---|
| 993 | </ol> |
|---|
| 994 | <p id="rfc.section.5.1.p.4">Server-driven negotiation allows the user agent to specify its preferences, but it cannot expect responses to always honour |
|---|
| 995 | them. For example, the origin server might not implement server-driven negotiation, or it might decide that sending a response |
|---|
| 996 | that doesn't conform to them is better than sending a 406 (Not Acceptable) response. |
|---|
| 997 | </p> |
|---|
| 998 | <p id="rfc.section.5.1.p.5">Many of the mechanisms for expressing preferences use quality values to declare relative preference. See <a href="p1-messaging.html#quality.values" title="Quality Values">Section 5.3</a> of <a href="#Part1" id="rfc.xref.Part1.17"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a> for more information. |
|---|
| 999 | </p> |
|---|
| 1000 | <p id="rfc.section.5.1.p.6">HTTP/1.1 includes the following header fields for enabling server-driven negotiation through description of user agent capabilities |
|---|
| 1001 | and user preferences: Accept (<a href="#header.accept" id="rfc.xref.header.accept.2" title="Accept">Section 6.1</a>), Accept-Charset (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.1" title="Accept-Charset">Section 6.2</a>), Accept-Encoding (<a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.2" title="Accept-Encoding">Section 6.3</a>), Accept-Language (<a href="#header.accept-language" id="rfc.xref.header.accept-language.1" title="Accept-Language">Section 6.4</a>), and User-Agent (<a href="p2-semantics.html#header.user-agent" title="User-Agent">Section 9.10</a> of <a href="#Part2" id="rfc.xref.Part2.1"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>). However, an origin server is not limited to these dimensions and <em class="bcp14">MAY</em> vary the response based on any aspect of the request, including aspects of the connection (e.g., IP address) or information |
|---|
| 1002 | within extension header fields not defined by this specification. |
|---|
| 1003 | </p> |
|---|
| 1004 | <div class="note" id="rfc.section.5.1.p.7"> |
|---|
| 1005 | <p> <b>Note:</b> In practice, User-Agent based negotiation is fragile, because new clients might not be recognized. |
|---|
| 1006 | </p> |
|---|
| 1007 | </div> |
|---|
| 1008 | <p id="rfc.section.5.1.p.8">The Vary header field (<a href="p6-cache.html#header.vary" title="Vary">Section 3.5</a> of <a href="#Part6" id="rfc.xref.Part6.2"><cite title="HTTP/1.1, part 6: Caching">[Part6]</cite></a>) can be used to express the parameters the server uses to select a representation that is subject to server-driven negotiation. |
|---|
| 1009 | </p> |
|---|
| 1010 | <h2 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2</a> <a id="agent-driven.negotiation" href="#agent-driven.negotiation">Agent-driven Negotiation</a></h2> |
|---|
| 1011 | <p id="rfc.section.5.2.p.1">With agent-driven negotiation, selection of the best representation for a response is performed by the user agent after receiving |
|---|
| 1012 | an initial response from the origin server. Selection is based on a list of the available representations of the response |
|---|
| 1013 | included within the header fields or body of the initial response, with each representation identified by its own URI. Selection |
|---|
| 1014 | from among the representations can be performed automatically (if the user agent is capable of doing so) or manually by the |
|---|
| 1015 | user selecting from a generated (possibly hypertext) menu. |
|---|
| 1016 | </p> |
|---|
| 1017 | <p id="rfc.section.5.2.p.2">Agent-driven negotiation is advantageous when the response would vary over commonly-used dimensions (such as type, language, |
|---|
| 1018 | or encoding), when the origin server is unable to determine a user agent's capabilities from examining the request, and generally |
|---|
| 1019 | when public caches are used to distribute server load and reduce network usage. |
|---|
| 1020 | </p> |
|---|
| 1021 | <p id="rfc.section.5.2.p.3">Agent-driven negotiation suffers from the disadvantage of needing a second request to obtain the best alternate representation. |
|---|
| 1022 | This second request is only efficient when caching is used. In addition, this specification does not define any mechanism |
|---|
| 1023 | for supporting automatic selection, though it also does not prevent any such mechanism from being developed as an extension |
|---|
| 1024 | and used within HTTP/1.1. |
|---|
| 1025 | </p> |
|---|
| 1026 | <p id="rfc.section.5.2.p.4">This specification defines the 300 (Multiple Choices) and 406 (Not Acceptable) status codes for enabling agent-driven negotiation |
|---|
| 1027 | when the server is unwilling or unable to provide a varying response using server-driven negotiation. |
|---|
| 1028 | </p> |
|---|
| 1029 | <h1 id="rfc.section.6"><a href="#rfc.section.6">6.</a> <a id="header.field.definitions" href="#header.field.definitions">Header Field Definitions</a></h1> |
|---|
| 1030 | <p id="rfc.section.6.p.1">This section defines the syntax and semantics of HTTP/1.1 header fields related to the payload of messages.</p> |
|---|
| 1031 | <div id="rfc.iref.a.1"></div> |
|---|
| 1032 | <div id="rfc.iref.h.1"></div> |
|---|
| 1033 | <h2 id="rfc.section.6.1"><a href="#rfc.section.6.1">6.1</a> <a id="header.accept" href="#header.accept">Accept</a></h2> |
|---|
| 1034 | <p id="rfc.section.6.1.p.1">The "Accept" header field can be used by user agents to specify response media types that are acceptable. Accept header fields |
|---|
| 1035 | can be used to indicate that the request is specifically limited to a small set of desired types, as in the case of a request |
|---|
| 1036 | for an in-line image. |
|---|
| 1037 | </p> |
|---|
| 1038 | <div id="rfc.figure.u.10"></div><pre class="inline"><span id="rfc.iref.g.11"></span><span id="rfc.iref.g.12"></span><span id="rfc.iref.g.13"></span><span id="rfc.iref.g.14"></span> <a href="#header.accept" class="smpl">Accept</a> = #( <a href="#header.accept" class="smpl">media-range</a> [ <a href="#header.accept" class="smpl">accept-params</a> ] ) |
|---|
| 1039 | |
|---|
| 1040 | <a href="#header.accept" class="smpl">media-range</a> = ( "*/*" |
|---|
| 1041 | / ( <a href="#media.types" class="smpl">type</a> "/" "*" ) |
|---|
| 1042 | / ( <a href="#media.types" class="smpl">type</a> "/" <a href="#media.types" class="smpl">subtype</a> ) |
|---|
| 1043 | ) *( <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> <a href="#rule.parameter" class="smpl">parameter</a> ) |
|---|
| 1044 | <a href="#header.accept" class="smpl">accept-params</a> = <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> "q=" <a href="#abnf.dependencies" class="smpl">qvalue</a> *( <a href="#header.accept" class="smpl">accept-ext</a> ) |
|---|
| 1045 | <a href="#header.accept" class="smpl">accept-ext</a> = <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> <a href="#core.rules" class="smpl">token</a> [ "=" <a href="#core.rules" class="smpl">word</a> ] |
|---|
| 1046 | </pre><p id="rfc.section.6.1.p.3">The asterisk "*" character is used to group media types into ranges, with "*/*" indicating all media types and "type/*" indicating |
|---|
| 1047 | all subtypes of that type. The media-range <em class="bcp14">MAY</em> include media type parameters that are applicable to that range. |
|---|
| 1048 | </p> |
|---|
| 1049 | <p id="rfc.section.6.1.p.4">Each media-range <em class="bcp14">MAY</em> be followed by one or more accept-params, beginning with the "q" parameter for indicating a relative quality factor. The first |
|---|
| 1050 | "q" parameter (if any) separates the media-range parameter(s) from the accept-params. Quality factors allow the user or user |
|---|
| 1051 | agent to indicate the relative degree of preference for that media-range, using the qvalue scale from 0 to 1 (<a href="p1-messaging.html#quality.values" title="Quality Values">Section 5.3</a> of <a href="#Part1" id="rfc.xref.Part1.18"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>). The default value is q=1. |
|---|
| 1052 | </p> |
|---|
| 1053 | <div class="note" id="rfc.section.6.1.p.5"> |
|---|
| 1054 | <p> <b>Note:</b> Use of the "q" parameter name to separate media type parameters from Accept extension parameters is due to historical practice. |
|---|
| 1055 | Although this prevents any media type parameter named "q" from being used with a media range, such an event is believed to |
|---|
| 1056 | be unlikely given the lack of any "q" parameters in the IANA media type registry and the rare usage of any media type parameters |
|---|
| 1057 | in Accept. Future media types are discouraged from registering any parameter named "q". |
|---|
| 1058 | </p> |
|---|
| 1059 | </div> |
|---|
| 1060 | <p id="rfc.section.6.1.p.6">The example</p> |
|---|
| 1061 | <div id="rfc.figure.u.11"></div><pre class="text"> Accept: audio/*; q=0.2, audio/basic |
|---|
| 1062 | </pre><p id="rfc.section.6.1.p.8"> <em class="bcp14">SHOULD</em> be interpreted as "I prefer audio/basic, but send me any audio type if it is the best available after an 80% mark-down in |
|---|
| 1063 | quality". |
|---|
| 1064 | </p> |
|---|
| 1065 | <p id="rfc.section.6.1.p.9">A request without any Accept header field implies that the user agent will accept any media type in response. If an Accept |
|---|
| 1066 | header field is present in a request and none of the available representations for the response have a media type that is |
|---|
| 1067 | listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept header field by sending a 406 (Not Acceptable) response or disregard the Accept header field by treating |
|---|
| 1068 | the response as if it is not subject to content negotiation. |
|---|
| 1069 | </p> |
|---|
| 1070 | <p id="rfc.section.6.1.p.10">A more elaborate example is</p> |
|---|
| 1071 | <div id="rfc.figure.u.12"></div><pre class="text"> Accept: text/plain; q=0.5, text/html, |
|---|
| 1072 | text/x-dvi; q=0.8, text/x-c |
|---|
| 1073 | </pre><p id="rfc.section.6.1.p.12">Verbally, this would be interpreted as "text/html and text/x-c are the preferred media types, but if they do not exist, then |
|---|
| 1074 | send the text/x-dvi representation, and if that does not exist, send the text/plain representation". |
|---|
| 1075 | </p> |
|---|
| 1076 | <p id="rfc.section.6.1.p.13">Media ranges can be overridden by more specific media ranges or specific media types. If more than one media range applies |
|---|
| 1077 | to a given type, the most specific reference has precedence. For example, |
|---|
| 1078 | </p> |
|---|
| 1079 | <div id="rfc.figure.u.13"></div><pre class="text"> Accept: text/*, text/plain, text/plain;format=flowed, */* |
|---|
| 1080 | </pre><p id="rfc.section.6.1.p.15">have the following precedence: </p> |
|---|
| 1081 | <ol> |
|---|
| 1082 | <li>text/plain;format=flowed</li> |
|---|
| 1083 | <li>text/plain</li> |
|---|
| 1084 | <li>text/*</li> |
|---|
| 1085 | <li>*/*</li> |
|---|
| 1086 | </ol> |
|---|
| 1087 | <p id="rfc.section.6.1.p.16">The media type quality factor associated with a given type is determined by finding the media range with the highest precedence |
|---|
| 1088 | which matches that type. For example, |
|---|
| 1089 | </p> |
|---|
| 1090 | <div id="rfc.figure.u.14"></div><pre class="text"> Accept: text/*;q=0.3, text/html;q=0.7, text/html;level=1, |
|---|
| 1091 | text/html;level=2;q=0.4, */*;q=0.5 |
|---|
| 1092 | </pre><p id="rfc.section.6.1.p.18">would cause the following values to be associated:</p> |
|---|
| 1093 | <div id="rfc.table.u.3"> |
|---|
| 1094 | <table class="tt full left" cellpadding="3" cellspacing="0"> |
|---|
| 1095 | <thead> |
|---|
| 1096 | <tr> |
|---|
| 1097 | <th>Media Type</th> |
|---|
| 1098 | <th>Quality Value</th> |
|---|
| 1099 | </tr> |
|---|
| 1100 | </thead> |
|---|
| 1101 | <tbody> |
|---|
| 1102 | <tr> |
|---|
| 1103 | <td class="left">text/html;level=1</td> |
|---|
| 1104 | <td class="left">1</td> |
|---|
| 1105 | </tr> |
|---|
| 1106 | <tr> |
|---|
| 1107 | <td class="left">text/html</td> |
|---|
| 1108 | <td class="left">0.7</td> |
|---|
| 1109 | </tr> |
|---|
| 1110 | <tr> |
|---|
| 1111 | <td class="left">text/plain</td> |
|---|
| 1112 | <td class="left">0.3</td> |
|---|
| 1113 | </tr> |
|---|
| 1114 | <tr> |
|---|
| 1115 | <td class="left">image/jpeg</td> |
|---|
| 1116 | <td class="left">0.5</td> |
|---|
| 1117 | </tr> |
|---|
| 1118 | <tr> |
|---|
| 1119 | <td class="left">text/html;level=2</td> |
|---|
| 1120 | <td class="left">0.4</td> |
|---|
| 1121 | </tr> |
|---|
| 1122 | <tr> |
|---|
| 1123 | <td class="left">text/html;level=3</td> |
|---|
| 1124 | <td class="left">0.7</td> |
|---|
| 1125 | </tr> |
|---|
| 1126 | </tbody> |
|---|
| 1127 | </table> |
|---|
| 1128 | </div> |
|---|
| 1129 | <p id="rfc.section.6.1.p.19"> <b>Note:</b> A user agent might be provided with a default set of quality values for certain media ranges. However, unless the user agent |
|---|
| 1130 | is a closed system which cannot interact with other rendering agents, this default set ought to be configurable by the user. |
|---|
| 1131 | </p> |
|---|
| 1132 | <div id="rfc.iref.a.2"></div> |
|---|
| 1133 | <div id="rfc.iref.h.2"></div> |
|---|
| 1134 | <h2 id="rfc.section.6.2"><a href="#rfc.section.6.2">6.2</a> <a id="header.accept-charset" href="#header.accept-charset">Accept-Charset</a></h2> |
|---|
| 1135 | <p id="rfc.section.6.2.p.1">The "Accept-Charset" header field can be used by user agents to indicate what character encodings are acceptable in a response |
|---|
| 1136 | payload. This field allows clients capable of understanding more comprehensive or special-purpose character encodings to signal |
|---|
| 1137 | that capability to a server which is capable of representing documents in those character encodings. |
|---|
| 1138 | </p> |
|---|
| 1139 | <div id="rfc.figure.u.15"></div><pre class="inline"><span id="rfc.iref.g.15"></span> <a href="#header.accept-charset" class="smpl">Accept-Charset</a> = 1#( ( <a href="#rule.charset" class="smpl">charset</a> / "*" ) |
|---|
| 1140 | [ <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> "q=" <a href="#abnf.dependencies" class="smpl">qvalue</a> ] ) |
|---|
| 1141 | </pre><p id="rfc.section.6.2.p.3">Character encoding values (a.k.a., charsets) are described in <a href="#character.sets" title="Character Encodings (charset)">Section 2.1</a>. Each charset <em class="bcp14">MAY</em> be given an associated quality value which represents the user's preference for that charset. The default value is q=1. An |
|---|
| 1142 | example is |
|---|
| 1143 | </p> |
|---|
| 1144 | <div id="rfc.figure.u.16"></div><pre class="text"> Accept-Charset: iso-8859-5, unicode-1-1;q=0.8 |
|---|
| 1145 | </pre><p id="rfc.section.6.2.p.5">The special value "*", if present in the Accept-Charset field, matches every character encoding which is not mentioned elsewhere |
|---|
| 1146 | in the Accept-Charset field. If no "*" is present in an Accept-Charset field, then all character encodings not explicitly |
|---|
| 1147 | mentioned get a quality value of 0. |
|---|
| 1148 | </p> |
|---|
| 1149 | <p id="rfc.section.6.2.p.6">A request without any Accept-Charset header field implies that the user agent will accept any character encoding in response. |
|---|
| 1150 | If an Accept-Charset header field is present in a request and none of the available representations for the response have |
|---|
| 1151 | a character encoding that is listed as acceptable, the origin server <em class="bcp14">MAY</em> either honor the Accept-Charset header field by sending a 406 (Not Acceptable) response or disregard the Accept-Charset header |
|---|
| 1152 | field by treating the response as if it is not subject to content negotiation. |
|---|
| 1153 | </p> |
|---|
| 1154 | <div id="rfc.iref.a.3"></div> |
|---|
| 1155 | <div id="rfc.iref.h.3"></div> |
|---|
| 1156 | <h2 id="rfc.section.6.3"><a href="#rfc.section.6.3">6.3</a> <a id="header.accept-encoding" href="#header.accept-encoding">Accept-Encoding</a></h2> |
|---|
| 1157 | <p id="rfc.section.6.3.p.1">The "Accept-Encoding" header field can be used by user agents to indicate what response content-codings (<a href="#content.codings" title="Content Codings">Section 2.2</a>) are acceptable in the response. An "identity" token is used as a synonym for "no encoding" in order to communicate when |
|---|
| 1158 | no encoding is preferred. |
|---|
| 1159 | </p> |
|---|
| 1160 | <div id="rfc.figure.u.17"></div><pre class="inline"><span id="rfc.iref.g.16"></span><span id="rfc.iref.g.17"></span> <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> = #( <a href="#header.accept-encoding" class="smpl">codings</a> [ <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> "q=" <a href="#abnf.dependencies" class="smpl">qvalue</a> ] ) |
|---|
| 1161 | <a href="#header.accept-encoding" class="smpl">codings</a> = <a href="#content.codings" class="smpl">content-coding</a> / "identity" / "*" |
|---|
| 1162 | </pre><p id="rfc.section.6.3.p.3">Each codings value <em class="bcp14">MAY</em> be given an associated quality value which represents the preference for that encoding. The default value is q=1. |
|---|
| 1163 | </p> |
|---|
| 1164 | <p id="rfc.section.6.3.p.4">For example,</p> |
|---|
| 1165 | <div id="rfc.figure.u.18"></div><pre class="text"> Accept-Encoding: compress, gzip |
|---|
| 1166 | Accept-Encoding: |
|---|
| 1167 | Accept-Encoding: * |
|---|
| 1168 | Accept-Encoding: compress;q=0.5, gzip;q=1.0 |
|---|
| 1169 | Accept-Encoding: gzip;q=1.0, identity; q=0.5, *;q=0 |
|---|
| 1170 | </pre><p id="rfc.section.6.3.p.6">A server tests whether a content-coding for a given representation is acceptable, according to an Accept-Encoding field, using |
|---|
| 1171 | these rules: |
|---|
| 1172 | </p> |
|---|
| 1173 | <ol> |
|---|
| 1174 | <li>The special "*" symbol in an Accept-Encoding field matches any available content-coding not explicitly listed in the header |
|---|
| 1175 | field. |
|---|
| 1176 | </li> |
|---|
| 1177 | <li>If the representation has no content-coding, then it is acceptable by default unless specifically excluded by the Accept-Encoding |
|---|
| 1178 | field stating either "identity;q=0" or "*;q=0" without a more specific entry for "identity". |
|---|
| 1179 | </li> |
|---|
| 1180 | <li>If the representation's content-coding is one of the content-codings listed in the Accept-Encoding field, then it is acceptable |
|---|
| 1181 | unless it is accompanied by a qvalue of 0. (As defined in <a href="p1-messaging.html#quality.values" title="Quality Values">Section 5.3</a> of <a href="#Part1" id="rfc.xref.Part1.19"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>, a qvalue of 0 means "not acceptable".) |
|---|
| 1182 | </li> |
|---|
| 1183 | <li>If multiple content-codings are acceptable, then the acceptable content-coding with the highest non-zero qvalue is preferred.</li> |
|---|
| 1184 | </ol> |
|---|
| 1185 | <p id="rfc.section.6.3.p.7">An Accept-Encoding header field with a combined field-value that is empty implies that the user agent does not want any content-coding |
|---|
| 1186 | in response. If an Accept-Encoding header field is present in a request and none of the available representations for the |
|---|
| 1187 | response have a content-coding that is listed as acceptable, the origin server <em class="bcp14">SHOULD</em> send a response without any content-coding. |
|---|
| 1188 | </p> |
|---|
| 1189 | <p id="rfc.section.6.3.p.8">A request without an Accept-Encoding header field implies that the user agent will accept any content-coding in response, |
|---|
| 1190 | but a representation without content-coding is preferred for compatibility with the widest variety of user agents. |
|---|
| 1191 | </p> |
|---|
| 1192 | <div class="note" id="rfc.section.6.3.p.9"> |
|---|
| 1193 | <p> <b>Note:</b> Most HTTP/1.0 applications do not recognize or obey qvalues associated with content-codings. This means that qvalues will |
|---|
| 1194 | not work and are not permitted with x-gzip or x-compress. |
|---|
| 1195 | </p> |
|---|
| 1196 | </div> |
|---|
| 1197 | <div id="rfc.iref.a.4"></div> |
|---|
| 1198 | <div id="rfc.iref.h.4"></div> |
|---|
| 1199 | <h2 id="rfc.section.6.4"><a href="#rfc.section.6.4">6.4</a> <a id="header.accept-language" href="#header.accept-language">Accept-Language</a></h2> |
|---|
| 1200 | <p id="rfc.section.6.4.p.1">The "Accept-Language" header field can be used by user agents to indicate the set of natural languages that are preferred |
|---|
| 1201 | in the response. Language tags are defined in <a href="#language.tags" title="Language Tags">Section 2.4</a>. |
|---|
| 1202 | </p> |
|---|
| 1203 | <div id="rfc.figure.u.19"></div><pre class="inline"><span id="rfc.iref.g.18"></span><span id="rfc.iref.g.19"></span> <a href="#header.accept-language" class="smpl">Accept-Language</a> = |
|---|
| 1204 | 1#( <a href="#header.accept-language" class="smpl">language-range</a> [ <a href="#core.rules" class="smpl">OWS</a> ";" <a href="#core.rules" class="smpl">OWS</a> "q=" <a href="#abnf.dependencies" class="smpl">qvalue</a> ] ) |
|---|
| 1205 | <a href="#header.accept-language" class="smpl">language-range</a> = |
|---|
| 1206 | <language-range, defined in <a href="#RFC4647" id="rfc.xref.RFC4647.1"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-2.1">Section 2.1</a>> |
|---|
| 1207 | </pre><p id="rfc.section.6.4.p.3">Each language-range can be given an associated quality value which represents an estimate of the user's preference for the |
|---|
| 1208 | languages specified by that range. The quality value defaults to "q=1". For example, |
|---|
| 1209 | </p> |
|---|
| 1210 | <div id="rfc.figure.u.20"></div><pre class="text"> Accept-Language: da, en-gb;q=0.8, en;q=0.7 |
|---|
| 1211 | </pre><p id="rfc.section.6.4.p.5">would mean: "I prefer Danish, but will accept British English and other types of English". (see also <a href="http://tools.ietf.org/html/rfc4647#section-2.3">Section 2.3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.2"><cite title="Matching of Language Tags">[RFC4647]</cite></a>) |
|---|
| 1212 | </p> |
|---|
| 1213 | <p id="rfc.section.6.4.p.6">For matching, <a href="http://tools.ietf.org/html/rfc4647#section-3">Section 3</a> of <a href="#RFC4647" id="rfc.xref.RFC4647.3"><cite title="Matching of Language Tags">[RFC4647]</cite></a> defines several matching schemes. Implementations can offer the most appropriate matching scheme for their requirements. |
|---|
| 1214 | </p> |
|---|
| 1215 | <div class="note" id="rfc.section.6.4.p.7"> |
|---|
| 1216 | <p> <b>Note:</b> The "Basic Filtering" scheme (<a href="#RFC4647" id="rfc.xref.RFC4647.4"><cite title="Matching of Language Tags">[RFC4647]</cite></a>, <a href="http://tools.ietf.org/html/rfc4647#section-3.3.1">Section 3.3.1</a>) is identical to the matching scheme that was previously defined in <a href="http://tools.ietf.org/html/rfc2616#section-14.4">Section 14.4</a> of <a href="#RFC2616" id="rfc.xref.RFC2616.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>. |
|---|
| 1217 | </p> |
|---|
| 1218 | </div> |
|---|
| 1219 | <p id="rfc.section.6.4.p.8">It might be contrary to the privacy expectations of the user to send an Accept-Language header field with the complete linguistic |
|---|
| 1220 | preferences of the user in every request. For a discussion of this issue, see <a href="#privacy.issues.connected.to.accept.header.fields" title="Privacy Issues Connected to Accept Header Fields">Section 8.1</a>. |
|---|
| 1221 | </p> |
|---|
| 1222 | <p id="rfc.section.6.4.p.9">As intelligibility is highly dependent on the individual user, it is recommended that client applications make the choice |
|---|
| 1223 | of linguistic preference available to the user. If the choice is not made available, then the Accept-Language header field <em class="bcp14">MUST NOT</em> be given in the request. |
|---|
| 1224 | </p> |
|---|
| 1225 | <div class="note" id="rfc.section.6.4.p.10"> |
|---|
| 1226 | <p> <b>Note:</b> When making the choice of linguistic preference available to the user, we remind implementors of the fact that users are not |
|---|
| 1227 | familiar with the details of language matching as described above, and ought to be provided appropriate guidance. As an example, |
|---|
| 1228 | users might assume that on selecting "en-gb", they will be served any kind of English document if British English is not available. |
|---|
| 1229 | A user agent might suggest in such a case to add "en" to get the best matching behavior. |
|---|
| 1230 | </p> |
|---|
| 1231 | </div> |
|---|
| 1232 | <div id="rfc.iref.c.6"></div> |
|---|
| 1233 | <div id="rfc.iref.h.5"></div> |
|---|
| 1234 | <h2 id="rfc.section.6.5"><a href="#rfc.section.6.5">6.5</a> <a id="header.content-encoding" href="#header.content-encoding">Content-Encoding</a></h2> |
|---|
| 1235 | <p id="rfc.section.6.5.p.1">The "Content-Encoding" header field indicates what content-codings have been applied to the representation beyond those inherent |
|---|
| 1236 | in the media type, and thus what decoding mechanisms must be applied in order to obtain the media-type referenced by the Content-Type |
|---|
| 1237 | header field. Content-Encoding is primarily used to allow a representation to be compressed without losing the identity of |
|---|
| 1238 | its underlying media type. |
|---|
| 1239 | </p> |
|---|
| 1240 | <div id="rfc.figure.u.21"></div><pre class="inline"><span id="rfc.iref.g.20"></span> <a href="#header.content-encoding" class="smpl">Content-Encoding</a> = 1#<a href="#content.codings" class="smpl">content-coding</a> |
|---|
| 1241 | </pre><p id="rfc.section.6.5.p.3">Content codings are defined in <a href="#content.codings" title="Content Codings">Section 2.2</a>. An example of its use is |
|---|
| 1242 | </p> |
|---|
| 1243 | <div id="rfc.figure.u.22"></div><pre class="text"> Content-Encoding: gzip |
|---|
| 1244 | </pre><p id="rfc.section.6.5.p.5">The content-coding is a characteristic of the representation. Typically, the representation body is stored with this encoding |
|---|
| 1245 | and is only decoded before rendering or analogous usage. However, a transforming proxy <em class="bcp14">MAY</em> modify the content-coding if the new coding is known to be acceptable to the recipient, unless the "no-transform" cache-control |
|---|
| 1246 | directive is present in the message. |
|---|
| 1247 | </p> |
|---|
| 1248 | <p id="rfc.section.6.5.p.6">If the media type includes an inherent encoding, such as a data format that is always compressed, then that encoding would |
|---|
| 1249 | not be restated as a Content-Encoding even if it happens to be the same algorithm as one of the content-codings. Such a content-coding |
|---|
| 1250 | would only be listed if, for some bizarre reason, it is applied a second time to form the representation. Likewise, an origin |
|---|
| 1251 | server might choose to publish the same payload data as multiple representations that differ only in whether the coding is |
|---|
| 1252 | defined as part of Content-Type or Content-Encoding, since some user agents will behave differently in their handling of each |
|---|
| 1253 | response (e.g., open a "Save as ..." dialog instead of automatic decompression and rendering of content). |
|---|
| 1254 | </p> |
|---|
| 1255 | <p id="rfc.section.6.5.p.7">A representation that has a content-coding applied to it <em class="bcp14">MUST</em> include a Content-Encoding header field (<a href="#header.content-encoding" id="rfc.xref.header.content-encoding.3" title="Content-Encoding">Section 6.5</a>) that lists the content-coding(s) applied. |
|---|
| 1256 | </p> |
|---|
| 1257 | <p id="rfc.section.6.5.p.8">If multiple encodings have been applied to a representation, the content codings <em class="bcp14">MUST</em> be listed in the order in which they were applied. Additional information about the encoding parameters <em class="bcp14">MAY</em> be provided by other header fields not defined by this specification. |
|---|
| 1258 | </p> |
|---|
| 1259 | <p id="rfc.section.6.5.p.9">If the content-coding of a representation in a request message is not acceptable to the origin server, the server <em class="bcp14">SHOULD</em> respond with a status code of 415 (Unsupported Media Type). |
|---|
| 1260 | </p> |
|---|
| 1261 | <div id="rfc.iref.c.7"></div> |
|---|
| 1262 | <div id="rfc.iref.h.6"></div> |
|---|
| 1263 | <h2 id="rfc.section.6.6"><a href="#rfc.section.6.6">6.6</a> <a id="header.content-language" href="#header.content-language">Content-Language</a></h2> |
|---|
| 1264 | <p id="rfc.section.6.6.p.1">The "Content-Language" header field describes the natural language(s) of the intended audience for the representation. Note |
|---|
| 1265 | that this might not be equivalent to all the languages used within the representation. |
|---|
| 1266 | </p> |
|---|
| 1267 | <div id="rfc.figure.u.23"></div><pre class="inline"><span id="rfc.iref.g.21"></span> <a href="#header.content-language" class="smpl">Content-Language</a> = 1#<a href="#language.tags" class="smpl">language-tag</a> |
|---|
| 1268 | </pre><p id="rfc.section.6.6.p.3">Language tags are defined in <a href="#language.tags" title="Language Tags">Section 2.4</a>. The primary purpose of Content-Language is to allow a user to identify and differentiate representations according to the |
|---|
| 1269 | user's own preferred language. Thus, if the body content is intended only for a Danish-literate audience, the appropriate |
|---|
| 1270 | field is |
|---|
| 1271 | </p> |
|---|
| 1272 | <div id="rfc.figure.u.24"></div><pre class="text"> Content-Language: da |
|---|
| 1273 | </pre><p id="rfc.section.6.6.p.5">If no Content-Language is specified, the default is that the content is intended for all language audiences. This might mean |
|---|
| 1274 | that the sender does not consider it to be specific to any natural language, or that the sender does not know for which language |
|---|
| 1275 | it is intended. |
|---|
| 1276 | </p> |
|---|
| 1277 | <p id="rfc.section.6.6.p.6">Multiple languages <em class="bcp14">MAY</em> be listed for content that is intended for multiple audiences. For example, a rendition of the "Treaty of Waitangi", presented |
|---|
| 1278 | simultaneously in the original Maori and English versions, would call for |
|---|
| 1279 | </p> |
|---|
| 1280 | <div id="rfc.figure.u.25"></div><pre class="text"> Content-Language: mi, en |
|---|
| 1281 | </pre><p id="rfc.section.6.6.p.8">However, just because multiple languages are present within a representation does not mean that it is intended for multiple |
|---|
| 1282 | linguistic audiences. An example would be a beginner's language primer, such as "A First Lesson in Latin", which is clearly |
|---|
| 1283 | intended to be used by an English-literate audience. In this case, the Content-Language would properly only include "en". |
|---|
| 1284 | </p> |
|---|
| 1285 | <p id="rfc.section.6.6.p.9">Content-Language <em class="bcp14">MAY</em> be applied to any media type — it is not limited to textual documents. |
|---|
| 1286 | </p> |
|---|
| 1287 | <div id="rfc.iref.c.8"></div> |
|---|
| 1288 | <div id="rfc.iref.h.7"></div> |
|---|
| 1289 | <h2 id="rfc.section.6.7"><a href="#rfc.section.6.7">6.7</a> <a id="header.content-location" href="#header.content-location">Content-Location</a></h2> |
|---|
| 1290 | <p id="rfc.section.6.7.p.1">The "Content-Location" header field supplies a URI that can be used as a specific identifier for the representation in this |
|---|
| 1291 | message. In other words, if one were to perform a GET on this URI at the time of this message's generation, then a 200 response |
|---|
| 1292 | would contain the same representation that is enclosed as payload in this message. |
|---|
| 1293 | </p> |
|---|
| 1294 | <div id="rfc.figure.u.26"></div><pre class="inline"><span id="rfc.iref.g.22"></span> <a href="#header.content-location" class="smpl">Content-Location</a> = <a href="#abnf.dependencies" class="smpl">absolute-URI</a> / <a href="#abnf.dependencies" class="smpl">partial-URI</a> |
|---|
| 1295 | </pre><p id="rfc.section.6.7.p.3">The Content-Location value is not a replacement for the effective Request URI (<a href="p1-messaging.html#effective.request.uri" title="Effective Request URI">Section 4.3</a> of <a href="#Part1" id="rfc.xref.Part1.20"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>). It is representation metadata. It has the same syntax and semantics as the header field of the same name defined for MIME |
|---|
| 1296 | body parts in <a href="http://tools.ietf.org/html/rfc2557#section-4">Section 4</a> of <a href="#RFC2557" id="rfc.xref.RFC2557.1"><cite title="MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)">[RFC2557]</cite></a>. However, its appearance in an HTTP message has some special implications for HTTP recipients. |
|---|
| 1297 | </p> |
|---|
| 1298 | <p id="rfc.section.6.7.p.4">If Content-Location is included in a response message and its value is the same as the effective request URI, then the response |
|---|
| 1299 | payload <em class="bcp14">SHOULD</em> be considered the current representation of that resource. For a GET or HEAD request, this is the same as the default semantics |
|---|
| 1300 | when no Content-Location is provided by the server. For a state-changing request like PUT or POST, it implies that the server's |
|---|
| 1301 | response contains the new representation of that resource, thereby distinguishing it from representations that might only |
|---|
| 1302 | report about the action (e.g., "It worked!"). This allows authoring applications to update their local copies without the |
|---|
| 1303 | need for a subsequent GET request. |
|---|
| 1304 | </p> |
|---|
| 1305 | <p id="rfc.section.6.7.p.5">If Content-Location is included in a response message and its value differs from the effective request URI, then the origin |
|---|
| 1306 | server is informing recipients that this representation has its own, presumably more specific, identifier. For a GET or HEAD |
|---|
| 1307 | request, this is an indication that the effective request URI identifies a resource that is subject to content negotiation |
|---|
| 1308 | and the representation selected for this response can also be found at the identified URI. For other methods, such a Content-Location |
|---|
| 1309 | indicates that this representation contains a report on the action's status and the same report is available (for future access |
|---|
| 1310 | with GET) at the given URI. For example, a purchase transaction made via a POST request might include a receipt document as |
|---|
| 1311 | the payload of the 200 response; the Content-Location value provides an identifier for retrieving a copy of that same receipt |
|---|
| 1312 | in the future. |
|---|
| 1313 | </p> |
|---|
| 1314 | <p id="rfc.section.6.7.p.6">If Content-Location is included in a request message, then it <em class="bcp14">MAY</em> be interpreted by the origin server as an indication of where the user agent originally obtained the content of the enclosed |
|---|
| 1315 | representation (prior to any subsequent modification of the content by that user agent). In other words, the user agent is |
|---|
| 1316 | providing the same representation metadata that it received with the original representation. However, such interpretation <em class="bcp14">MUST NOT</em> be used to alter the semantics of the method requested by the client. For example, if a client makes a PUT request on a negotiated |
|---|
| 1317 | resource and the origin server accepts that PUT (without redirection), then the new set of values for that resource is expected |
|---|
| 1318 | to be consistent with the one representation supplied in that PUT; the Content-Location cannot be used as a form of reverse |
|---|
| 1319 | content selection that identifies only one of the negotiated representations to be updated. If the user agent had wanted the |
|---|
| 1320 | latter semantics, it would have applied the PUT directly to the Content-Location URI. |
|---|
| 1321 | </p> |
|---|
| 1322 | <p id="rfc.section.6.7.p.7">A Content-Location field received in a request message is transitory information that <em class="bcp14">SHOULD NOT</em> be saved with other representation metadata for use in later responses. The Content-Location's value might be saved for use |
|---|
| 1323 | in other contexts, such as within source links or other metadata. |
|---|
| 1324 | </p> |
|---|
| 1325 | <p id="rfc.section.6.7.p.8">A cache cannot assume that a representation with a Content-Location different from the URI used to retrieve it can be used |
|---|
| 1326 | to respond to later requests on that Content-Location URI. |
|---|
| 1327 | </p> |
|---|
| 1328 | <p id="rfc.section.6.7.p.9">If the Content-Location value is a partial URI, the partial URI is interpreted relative to the effective request URI.</p> |
|---|
| 1329 | <div id="rfc.iref.c.9"></div> |
|---|
| 1330 | <div id="rfc.iref.h.8"></div> |
|---|
| 1331 | <h2 id="rfc.section.6.8"><a href="#rfc.section.6.8">6.8</a> <a id="header.content-type" href="#header.content-type">Content-Type</a></h2> |
|---|
| 1332 | <p id="rfc.section.6.8.p.1">The "Content-Type" header field indicates the media type of the representation. In the case of responses to the HEAD method, |
|---|
| 1333 | the media type is that which would have been sent had the request been a GET. |
|---|
| 1334 | </p> |
|---|
| 1335 | <div id="rfc.figure.u.27"></div><pre class="inline"><span id="rfc.iref.g.23"></span> <a href="#header.content-type" class="smpl">Content-Type</a> = <a href="#media.types" class="smpl">media-type</a> |
|---|
| 1336 | </pre><p id="rfc.section.6.8.p.3">Media types are defined in <a href="#media.types" title="Media Types">Section 2.3</a>. An example of the field is |
|---|
| 1337 | </p> |
|---|
| 1338 | <div id="rfc.figure.u.28"></div><pre class="text"> Content-Type: text/html; charset=ISO-8859-4 |
|---|
| 1339 | </pre><p id="rfc.section.6.8.p.5">Further discussion of Content-Type is provided in <a href="#representation.data" title="Representation Data">Section 4.2</a>. |
|---|
| 1340 | </p> |
|---|
| 1341 | <h1 id="rfc.section.7"><a href="#rfc.section.7">7.</a> <a id="IANA.considerations" href="#IANA.considerations">IANA Considerations</a></h1> |
|---|
| 1342 | <h2 id="rfc.section.7.1"><a href="#rfc.section.7.1">7.1</a> <a id="header.field.registration" href="#header.field.registration">Header Field Registration</a></h2> |
|---|
| 1343 | <p id="rfc.section.7.1.p.1">The Message Header Field Registry located at <<a href="http://www.iana.org/assignments/message-headers/message-header-index.html">http://www.iana.org/assignments/message-headers/message-header-index.html</a>> shall be updated with the permanent registrations below (see <a href="#RFC3864" id="rfc.xref.RFC3864.1"><cite title="Registration Procedures for Message Header Fields">[RFC3864]</cite></a>): |
|---|
| 1344 | </p> |
|---|
| 1345 | <div id="rfc.table.1"> |
|---|
| 1346 | <div id="iana.header.registration.table"></div> |
|---|
| 1347 | <table class="tt full left" cellpadding="3" cellspacing="0"> |
|---|
| 1348 | <thead> |
|---|
| 1349 | <tr> |
|---|
| 1350 | <th>Header Field Name</th> |
|---|
| 1351 | <th>Protocol</th> |
|---|
| 1352 | <th>Status</th> |
|---|
| 1353 | <th>Reference</th> |
|---|
| 1354 | </tr> |
|---|
| 1355 | </thead> |
|---|
| 1356 | <tbody> |
|---|
| 1357 | <tr> |
|---|
| 1358 | <td class="left">Accept</td> |
|---|
| 1359 | <td class="left">http</td> |
|---|
| 1360 | <td class="left">standard</td> |
|---|
| 1361 | <td class="left"> <a href="#header.accept" id="rfc.xref.header.accept.3" title="Accept">Section 6.1</a> |
|---|
| 1362 | </td> |
|---|
| 1363 | </tr> |
|---|
| 1364 | <tr> |
|---|
| 1365 | <td class="left">Accept-Charset</td> |
|---|
| 1366 | <td class="left">http</td> |
|---|
| 1367 | <td class="left">standard</td> |
|---|
| 1368 | <td class="left"> <a href="#header.accept-charset" id="rfc.xref.header.accept-charset.2" title="Accept-Charset">Section 6.2</a> |
|---|
| 1369 | </td> |
|---|
| 1370 | </tr> |
|---|
| 1371 | <tr> |
|---|
| 1372 | <td class="left">Accept-Encoding</td> |
|---|
| 1373 | <td class="left">http</td> |
|---|
| 1374 | <td class="left">standard</td> |
|---|
| 1375 | <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.3" title="Accept-Encoding">Section 6.3</a> |
|---|
| 1376 | </td> |
|---|
| 1377 | </tr> |
|---|
| 1378 | <tr> |
|---|
| 1379 | <td class="left">Accept-Language</td> |
|---|
| 1380 | <td class="left">http</td> |
|---|
| 1381 | <td class="left">standard</td> |
|---|
| 1382 | <td class="left"> <a href="#header.accept-language" id="rfc.xref.header.accept-language.2" title="Accept-Language">Section 6.4</a> |
|---|
| 1383 | </td> |
|---|
| 1384 | </tr> |
|---|
| 1385 | <tr> |
|---|
| 1386 | <td class="left">Content-Encoding</td> |
|---|
| 1387 | <td class="left">http</td> |
|---|
| 1388 | <td class="left">standard</td> |
|---|
| 1389 | <td class="left"> <a href="#header.content-encoding" id="rfc.xref.header.content-encoding.4" title="Content-Encoding">Section 6.5</a> |
|---|
| 1390 | </td> |
|---|
| 1391 | </tr> |
|---|
| 1392 | <tr> |
|---|
| 1393 | <td class="left">Content-Language</td> |
|---|
| 1394 | <td class="left">http</td> |
|---|
| 1395 | <td class="left">standard</td> |
|---|
| 1396 | <td class="left"> <a href="#header.content-language" id="rfc.xref.header.content-language.2" title="Content-Language">Section 6.6</a> |
|---|
| 1397 | </td> |
|---|
| 1398 | </tr> |
|---|
| 1399 | <tr> |
|---|
| 1400 | <td class="left">Content-Location</td> |
|---|
| 1401 | <td class="left">http</td> |
|---|
| 1402 | <td class="left">standard</td> |
|---|
| 1403 | <td class="left"> <a href="#header.content-location" id="rfc.xref.header.content-location.2" title="Content-Location">Section 6.7</a> |
|---|
| 1404 | </td> |
|---|
| 1405 | </tr> |
|---|
| 1406 | <tr> |
|---|
| 1407 | <td class="left">Content-Type</td> |
|---|
| 1408 | <td class="left">http</td> |
|---|
| 1409 | <td class="left">standard</td> |
|---|
| 1410 | <td class="left"> <a href="#header.content-type" id="rfc.xref.header.content-type.3" title="Content-Type">Section 6.8</a> |
|---|
| 1411 | </td> |
|---|
| 1412 | </tr> |
|---|
| 1413 | <tr> |
|---|
| 1414 | <td class="left">MIME-Version</td> |
|---|
| 1415 | <td class="left">http</td> |
|---|
| 1416 | <td class="left">standard</td> |
|---|
| 1417 | <td class="left"> <a href="#mime-version" id="rfc.xref.mime-version.1" title="MIME-Version">Appendix A.1</a> |
|---|
| 1418 | </td> |
|---|
| 1419 | </tr> |
|---|
| 1420 | </tbody> |
|---|
| 1421 | </table> |
|---|
| 1422 | </div> |
|---|
| 1423 | <p id="rfc.section.7.1.p.2">The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".</p> |
|---|
| 1424 | <h2 id="rfc.section.7.2"><a href="#rfc.section.7.2">7.2</a> <a id="content.coding.registration" href="#content.coding.registration">Content Coding Registry</a></h2> |
|---|
| 1425 | <p id="rfc.section.7.2.p.1">The registration procedure for HTTP Content Codings is now defined by <a href="#content.coding.registry" title="Content Coding Registry">Section 2.2.1</a> of this document. |
|---|
| 1426 | </p> |
|---|
| 1427 | <p id="rfc.section.7.2.p.2">The HTTP Content Codings Registry located at <<a href="http://www.iana.org/assignments/http-parameters">http://www.iana.org/assignments/http-parameters</a>> shall be updated with the registration below: |
|---|
| 1428 | </p> |
|---|
| 1429 | <div id="rfc.table.2"> |
|---|
| 1430 | <div id="iana.content.coding.registration.table"></div> |
|---|
| 1431 | <table class="tt full left" cellpadding="3" cellspacing="0"> |
|---|
| 1432 | <thead> |
|---|
| 1433 | <tr> |
|---|
| 1434 | <th>Name</th> |
|---|
| 1435 | <th>Description</th> |
|---|
| 1436 | <th>Reference</th> |
|---|
| 1437 | </tr> |
|---|
| 1438 | </thead> |
|---|
| 1439 | <tbody> |
|---|
| 1440 | <tr> |
|---|
| 1441 | <td class="left">compress</td> |
|---|
| 1442 | <td class="left">UNIX "compress" program method</td> |
|---|
| 1443 | <td class="left"> <a href="p1-messaging.html#compress.coding" title="Compress Coding">Section 5.1.2.1</a> of <a href="#Part1" id="rfc.xref.Part1.21"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a> |
|---|
| 1444 | </td> |
|---|
| 1445 | </tr> |
|---|
| 1446 | <tr> |
|---|
| 1447 | <td class="left">deflate</td> |
|---|
| 1448 | <td class="left">"deflate" compression mechanism (<a href="#RFC1951" id="rfc.xref.RFC1951.1"><cite title="DEFLATE Compressed Data Format Specification version 1.3">[RFC1951]</cite></a>) used inside the "zlib" data format (<a href="#RFC1950" id="rfc.xref.RFC1950.1"><cite title="ZLIB Compressed Data Format Specification version 3.3">[RFC1950]</cite></a>) |
|---|
| 1449 | </td> |
|---|
| 1450 | <td class="left"> <a href="p1-messaging.html#deflate.coding" title="Deflate Coding">Section 5.1.2.2</a> of <a href="#Part1" id="rfc.xref.Part1.22"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a> |
|---|
| 1451 | </td> |
|---|
| 1452 | </tr> |
|---|
| 1453 | <tr> |
|---|
| 1454 | <td class="left">gzip</td> |
|---|
| 1455 | <td class="left">Same as GNU zip <a href="#RFC1952" id="rfc.xref.RFC1952.1"><cite title="GZIP file format specification version 4.3">[RFC1952]</cite></a></td> |
|---|
| 1456 | <td class="left"> <a href="p1-messaging.html#gzip.coding" title="Gzip Coding">Section 5.1.2.3</a> of <a href="#Part1" id="rfc.xref.Part1.23"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a> |
|---|
| 1457 | </td> |
|---|
| 1458 | </tr> |
|---|
| 1459 | <tr> |
|---|
| 1460 | <td class="left">identity</td> |
|---|
| 1461 | <td class="left">reserved (synonym for "no encoding" in Accept-Encoding header field)</td> |
|---|
| 1462 | <td class="left"> <a href="#header.accept-encoding" id="rfc.xref.header.accept-encoding.4" title="Accept-Encoding">Section 6.3</a> |
|---|
| 1463 | </td> |
|---|
| 1464 | </tr> |
|---|
| 1465 | </tbody> |
|---|
| 1466 | </table> |
|---|
| 1467 | </div> |
|---|
| 1468 | <h1 id="rfc.section.8"><a href="#rfc.section.8">8.</a> <a id="security.considerations" href="#security.considerations">Security Considerations</a></h1> |
|---|
| 1469 | <p id="rfc.section.8.p.1">This section is meant to inform application developers, information providers, and users of the security limitations in HTTP/1.1 |
|---|
| 1470 | as described by this document. The discussion does not include definitive solutions to the problems revealed, though it does |
|---|
| 1471 | make some suggestions for reducing security risks. |
|---|
| 1472 | </p> |
|---|
| 1473 | <h2 id="rfc.section.8.1"><a href="#rfc.section.8.1">8.1</a> <a id="privacy.issues.connected.to.accept.header.fields" href="#privacy.issues.connected.to.accept.header.fields">Privacy Issues Connected to Accept Header Fields</a></h2> |
|---|
| 1474 | <p id="rfc.section.8.1.p.1">Accept headers fields can reveal information about the user to all servers which are accessed. The Accept-Language header |
|---|
| 1475 | field in particular can reveal information the user would consider to be of a private nature, because the understanding of |
|---|
| 1476 | particular languages is often strongly correlated to the membership of a particular ethnic group. User agents which offer |
|---|
| 1477 | the option to configure the contents of an Accept-Language header field to be sent in every request are strongly encouraged |
|---|
| 1478 | to let the configuration process include a message which makes the user aware of the loss of privacy involved. |
|---|
| 1479 | </p> |
|---|
| 1480 | <p id="rfc.section.8.1.p.2">An approach that limits the loss of privacy would be for a user agent to omit the sending of Accept-Language header fields |
|---|
| 1481 | by default, and to ask the user whether or not to start sending Accept-Language header fields to a server if it detects, by |
|---|
| 1482 | looking for any Vary header fields generated by the server, that such sending could improve the quality of service. |
|---|
| 1483 | </p> |
|---|
| 1484 | <p id="rfc.section.8.1.p.3">Elaborate user-customized accept header fields sent in every request, in particular if these include quality values, can be |
|---|
| 1485 | used by servers as relatively reliable and long-lived user identifiers. Such user identifiers would allow content providers |
|---|
| 1486 | to do click-trail tracking, and would allow collaborating content providers to match cross-server click-trails or form submissions |
|---|
| 1487 | of individual users. Note that for many users not behind a proxy, the network address of the host running the user agent will |
|---|
| 1488 | also serve as a long-lived user identifier. In environments where proxies are used to enhance privacy, user agents ought to |
|---|
| 1489 | be conservative in offering accept header configuration options to end users. As an extreme privacy measure, proxies could |
|---|
| 1490 | filter the accept header fields in relayed requests. General purpose user agents which provide a high degree of header configurability <em class="bcp14">SHOULD</em> warn users about the loss of privacy which can be involved. |
|---|
| 1491 | </p> |
|---|
| 1492 | <h1 id="rfc.section.9"><a href="#rfc.section.9">9.</a> <a id="acks" href="#acks">Acknowledgments</a></h1> |
|---|
| 1493 | <p id="rfc.section.9.p.1">See <a href="p1-messaging.html#acks" title="Acknowledgments">Section 11</a> of <a href="#Part1" id="rfc.xref.Part1.24"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>. |
|---|
| 1494 | </p> |
|---|
| 1495 | <h1 id="rfc.references"><a id="rfc.section.10" href="#rfc.section.10">10.</a> References |
|---|
| 1496 | </h1> |
|---|
| 1497 | <h2 id="rfc.references.1"><a href="#rfc.section.10.1" id="rfc.section.10.1">10.1</a> Normative References |
|---|
| 1498 | </h2> |
|---|
| 1499 | <table> |
|---|
| 1500 | <tr> |
|---|
| 1501 | <td class="reference"><b id="Part1">[Part1]</b></td> |
|---|
| 1502 | <td class="top"><a href="mailto:fielding@gbiv.com" title="Adobe Systems Incorporated">Fielding, R., Ed.</a>, <a href="mailto:jg@freedesktop.org" title="Alcatel-Lucent Bell Labs">Gettys, J.</a>, <a href="mailto:JeffMogul@acm.org" title="Hewlett-Packard Company">Mogul, J.</a>, <a href="mailto:henrikn@microsoft.com" title="Microsoft Corporation">Frystyk, H.</a>, <a href="mailto:LMM@acm.org" title="Adobe Systems Incorporated">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com" title="Microsoft Corporation">Leach, P.</a>, <a href="mailto:timbl@w3.org" title="World Wide Web Consortium">Berners-Lee, T.</a>, <a href="mailto:ylafon@w3.org" title="World Wide Web Consortium">Lafon, Y., Ed.</a>, and <a href="mailto:julian.reschke@greenbytes.de" title="greenbytes GmbH">J. Reschke, Ed.</a>, “<a href="http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-latest">HTTP/1.1, part 1: URIs, Connections, and Message Parsing</a>”, Internet-Draft draft-ietf-httpbis-p1-messaging-latest (work in progress), October 2011. |
|---|
| 1503 | </td> |
|---|
| 1504 | </tr> |
|---|
| 1505 | <tr> |
|---|
| 1506 | <td class="reference"><b id="Part2">[Part2]</b></td> |
|---|
| 1507 | <td class="top"><a href="mailto:fielding@gbiv.com" title="Adobe Systems Incorporated">Fielding, R., Ed.</a>, <a href="mailto:jg@freedesktop.org" title="Alcatel-Lucent Bell Labs">Gettys, J.</a>, <a href="mailto:JeffMogul@acm.org" title="Hewlett-Packard Company">Mogul, J.</a>, <a href="mailto:henrikn@microsoft.com" title="Microsoft Corporation">Frystyk, H.</a>, <a href="mailto:LMM@acm.org" title="Adobe Systems Incorporated">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com" title="Microsoft Corporation">Leach, P.</a>, <a href="mailto:timbl@w3.org" title="World Wide Web Consortium">Berners-Lee, T.</a>, <a href="mailto:ylafon@w3.org" title="World Wide Web Consortium">Lafon, Y., Ed.</a>, and <a href="mailto:julian.reschke@greenbytes.de" title="greenbytes GmbH">J. Reschke, Ed.</a>, “<a href="http://tools.ietf.org/html/draft-ietf-httpbis-p2-semantics-latest">HTTP/1.1, part 2: Message Semantics</a>”, Internet-Draft draft-ietf-httpbis-p2-semantics-latest (work in progress), October 2011. |
|---|
| 1508 | </td> |
|---|
| 1509 | </tr> |
|---|
| 1510 | <tr> |
|---|
| 1511 | <td class="reference"><b id="Part4">[Part4]</b></td> |
|---|
| 1512 | <td class="top"><a href="mailto:fielding@gbiv.com" title="Adobe Systems Incorporated">Fielding, R., Ed.</a>, <a href="mailto:jg@freedesktop.org" title="Alcatel-Lucent Bell Labs">Gettys, J.</a>, <a href="mailto:JeffMogul@acm.org" title="Hewlett-Packard Company">Mogul, J.</a>, <a href="mailto:henrikn@microsoft.com" title="Microsoft Corporation">Frystyk, H.</a>, <a href="mailto:LMM@acm.org" title="Adobe Systems Incorporated">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com" title="Microsoft Corporation">Leach, P.</a>, <a href="mailto:timbl@w3.org" title="World Wide Web Consortium">Berners-Lee, T.</a>, <a href="mailto:ylafon@w3.org" title="World Wide Web Consortium">Lafon, Y., Ed.</a>, and <a href="mailto:julian.reschke@greenbytes.de" title="greenbytes GmbH">J. Reschke, Ed.</a>, “<a href="http://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-latest">HTTP/1.1, part 4: Conditional Requests</a>”, Internet-Draft draft-ietf-httpbis-p4-conditional-latest (work in progress), October 2011. |
|---|
| 1513 | </td> |
|---|
| 1514 | </tr> |
|---|
| 1515 | <tr> |
|---|
| 1516 | <td class="reference"><b id="Part5">[Part5]</b></td> |
|---|
| 1517 | <td class="top"><a href="mailto:fielding@gbiv.com" title="Adobe Systems Incorporated">Fielding, R., Ed.</a>, <a href="mailto:jg@freedesktop.org" title="Alcatel-Lucent Bell Labs">Gettys, J.</a>, <a href="mailto:JeffMogul@acm.org" title="Hewlett-Packard Company">Mogul, J.</a>, <a href="mailto:henrikn@microsoft.com" title="Microsoft Corporation">Frystyk, H.</a>, <a href="mailto:LMM@acm.org" title="Adobe Systems Incorporated">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com" title="Microsoft Corporation">Leach, P.</a>, <a href="mailto:timbl@w3.org" title="World Wide Web Consortium">Berners-Lee, T.</a>, <a href="mailto:ylafon@w3.org" title="World Wide Web Consortium">Lafon, Y., Ed.</a>, and <a href="mailto:julian.reschke@greenbytes.de" title="greenbytes GmbH">J. Reschke, Ed.</a>, “<a href="http://tools.ietf.org/html/draft-ietf-httpbis-p5-range-latest">HTTP/1.1, part 5: Range Requests and Partial Responses</a>”, Internet-Draft draft-ietf-httpbis-p5-range-latest (work in progress), October 2011. |
|---|
| 1518 | </td> |
|---|
| 1519 | </tr> |
|---|
| 1520 | <tr> |
|---|
| 1521 | <td class="reference"><b id="Part6">[Part6]</b></td> |
|---|
| 1522 | <td class="top"><a href="mailto:fielding@gbiv.com" title="Adobe Systems Incorporated">Fielding, R., Ed.</a>, <a href="mailto:jg@freedesktop.org" title="Alcatel-Lucent Bell Labs">Gettys, J.</a>, <a href="mailto:JeffMogul@acm.org" title="Hewlett-Packard Company">Mogul, J.</a>, <a href="mailto:henrikn@microsoft.com" title="Microsoft Corporation">Frystyk, H.</a>, <a href="mailto:LMM@acm.org" title="Adobe Systems Incorporated">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com" title="Microsoft Corporation">Leach, P.</a>, <a href="mailto:timbl@w3.org" title="World Wide Web Consortium">Berners-Lee, T.</a>, <a href="mailto:ylafon@w3.org" title="World Wide Web Consortium">Lafon, Y., Ed.</a>, <a href="mailto:mnot@mnot.net" title="Rackspace">Nottingham, M., Ed.</a>, and <a href="mailto:julian.reschke@greenbytes.de" title="greenbytes GmbH">J. Reschke, Ed.</a>, “<a href="http://tools.ietf.org/html/draft-ietf-httpbis-p6-cache-latest">HTTP/1.1, part 6: Caching</a>”, Internet-Draft draft-ietf-httpbis-p6-cache-latest (work in progress), October 2011. |
|---|
| 1523 | </td> |
|---|
| 1524 | </tr> |
|---|
| 1525 | <tr> |
|---|
| 1526 | <td class="reference"><b id="RFC1950">[RFC1950]</b></td> |
|---|
| 1527 | <td class="top"><a href="mailto:ghost@aladdin.com" title="Aladdin Enterprises">Deutsch, L.</a> and J-L. Gailly, “<a href="http://tools.ietf.org/html/rfc1950">ZLIB Compressed Data Format Specification version 3.3</a>”, RFC 1950, May 1996.<br>RFC 1950 is an Informational RFC, thus it might be less stable than this specification. On the other hand, this downward reference |
|---|
| 1528 | was present since the publication of <cite title="Hypertext Transfer Protocol -- HTTP/1.1" id="rfc.xref.RFC2068.1">RFC 2068</cite> in 1997, therefore it is unlikely to cause problems in practice. See also <a href="#BCP97" id="rfc.xref.BCP97.1"><cite title="Handling Normative References to Standards-Track Documents">[BCP97]</cite></a>. |
|---|
| 1529 | </td> |
|---|
| 1530 | </tr> |
|---|
| 1531 | <tr> |
|---|
| 1532 | <td class="reference"><b id="RFC1951">[RFC1951]</b></td> |
|---|
| 1533 | <td class="top"><a href="mailto:ghost@aladdin.com" title="Aladdin Enterprises">Deutsch, P.</a>, “<a href="http://tools.ietf.org/html/rfc1951">DEFLATE Compressed Data Format Specification version 1.3</a>”, RFC 1951, May 1996.<br>RFC 1951 is an Informational RFC, thus it might be less stable than this specification. On the other hand, this downward reference |
|---|
| 1534 | was present since the publication of <cite title="Hypertext Transfer Protocol -- HTTP/1.1" id="rfc.xref.RFC2068.2">RFC 2068</cite> in 1997, therefore it is unlikely to cause problems in practice. See also <a href="#BCP97" id="rfc.xref.BCP97.2"><cite title="Handling Normative References to Standards-Track Documents">[BCP97]</cite></a>. |
|---|
| 1535 | </td> |
|---|
| 1536 | </tr> |
|---|
| 1537 | <tr> |
|---|
| 1538 | <td class="reference"><b id="RFC1952">[RFC1952]</b></td> |
|---|
| 1539 | <td class="top"><a href="mailto:ghost@aladdin.com" title="Aladdin Enterprises">Deutsch, P.</a>, <a href="mailto:gzip@prep.ai.mit.edu">Gailly, J-L.</a>, <a href="mailto:madler@alumni.caltech.edu">Adler, M.</a>, <a href="mailto:ghost@aladdin.com">Deutsch, L.</a>, and <a href="mailto:randeg@alumni.rpi.edu">G. Randers-Pehrson</a>, “<a href="http://tools.ietf.org/html/rfc1952">GZIP file format specification version 4.3</a>”, RFC 1952, May 1996.<br>RFC 1952 is an Informational RFC, thus it might be less stable than this specification. On the other hand, this downward reference |
|---|
| 1540 | was present since the publication of <cite title="Hypertext Transfer Protocol -- HTTP/1.1" id="rfc.xref.RFC2068.3">RFC 2068</cite> in 1997, therefore it is unlikely to cause problems in practice. See also <a href="#BCP97" id="rfc.xref.BCP97.3"><cite title="Handling Normative References to Standards-Track Documents">[BCP97]</cite></a>. |
|---|
| 1541 | </td> |
|---|
| 1542 | </tr> |
|---|
| 1543 | <tr> |
|---|
| 1544 | <td class="reference"><b id="RFC2045">[RFC2045]</b></td> |
|---|
| 1545 | <td class="top"><a href="mailto:ned@innosoft.com" title="Innosoft International, Inc.">Freed, N.</a> and <a href="mailto:nsb@nsb.fv.com" title="First Virtual Holdings">N. Borenstein</a>, “<a href="http://tools.ietf.org/html/rfc2045">Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</a>”, RFC 2045, November 1996. |
|---|
| 1546 | </td> |
|---|
| 1547 | </tr> |
|---|
| 1548 | <tr> |
|---|
| 1549 | <td class="reference"><b id="RFC2046">[RFC2046]</b></td> |
|---|
| 1550 | <td class="top"><a href="mailto:ned@innosoft.com" title="Innosoft International, Inc.">Freed, N.</a> and <a href="mailto:nsb@nsb.fv.com" title="First Virtual Holdings">N. Borenstein</a>, “<a href="http://tools.ietf.org/html/rfc2046">Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types</a>”, RFC 2046, November 1996. |
|---|
| 1551 | </td> |
|---|
| 1552 | </tr> |
|---|
| 1553 | <tr> |
|---|
| 1554 | <td class="reference"><b id="RFC2119">[RFC2119]</b></td> |
|---|
| 1555 | <td class="top"><a href="mailto:sob@harvard.edu" title="Harvard University">Bradner, S.</a>, “<a href="http://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>”, BCP 14, RFC 2119, March 1997. |
|---|
| 1556 | </td> |
|---|
| 1557 | </tr> |
|---|
| 1558 | <tr> |
|---|
| 1559 | <td class="reference"><b id="RFC4647">[RFC4647]</b></td> |
|---|
| 1560 | <td class="top"><a href="mailto:addison@inter-locale.com" title="Yahoo! Inc.">Phillips, A., Ed.</a> and <a href="mailto:mark.davis@macchiato.com" title="Google">M. Davis, Ed.</a>, “<a href="http://tools.ietf.org/html/rfc4647">Matching of Language Tags</a>”, BCP 47, RFC 4647, September 2006. |
|---|
| 1561 | </td> |
|---|
| 1562 | </tr> |
|---|
| 1563 | <tr> |
|---|
| 1564 | <td class="reference"><b id="RFC5234">[RFC5234]</b></td> |
|---|
| 1565 | <td class="top"><a href="mailto:dcrocker@bbiw.net" title="Brandenburg InternetWorking">Crocker, D., Ed.</a> and <a href="mailto:paul.overell@thus.net" title="THUS plc.">P. Overell</a>, “<a href="http://tools.ietf.org/html/rfc5234">Augmented BNF for Syntax Specifications: ABNF</a>”, STD 68, RFC 5234, January 2008. |
|---|
| 1566 | </td> |
|---|
| 1567 | </tr> |
|---|
| 1568 | <tr> |
|---|
| 1569 | <td class="reference"><b id="RFC5646">[RFC5646]</b></td> |
|---|
| 1570 | <td class="top"><a href="mailto:addison@inter-locale.com" title="Lab126">Phillips, A., Ed.</a> and <a href="mailto:mark.davis@google.com" title="Google">M. Davis, Ed.</a>, “<a href="http://tools.ietf.org/html/rfc5646">Tags for Identifying Languages</a>”, BCP 47, RFC 5646, September 2009. |
|---|
| 1571 | </td> |
|---|
| 1572 | </tr> |
|---|
| 1573 | </table> |
|---|
| 1574 | <h2 id="rfc.references.2"><a href="#rfc.section.10.2" id="rfc.section.10.2">10.2</a> Informative References |
|---|
| 1575 | </h2> |
|---|
| 1576 | <table> |
|---|
| 1577 | <tr> |
|---|
| 1578 | <td class="reference"><b id="BCP97">[BCP97]</b></td> |
|---|
| 1579 | <td class="top"><a href="mailto:klensin+ietf@jck.com">Klensin, J.</a> and <a href="mailto:hartmans-ietf@mit.edu" title="MIT">S. Hartman</a>, “<a href="http://tools.ietf.org/html/rfc4897">Handling Normative References to Standards-Track Documents</a>”, BCP 97, RFC 4897, June 2007. |
|---|
| 1580 | </td> |
|---|
| 1581 | </tr> |
|---|
| 1582 | <tr> |
|---|
| 1583 | <td class="reference"><b id="RFC1945">[RFC1945]</b></td> |
|---|
| 1584 | <td class="top"><a href="mailto:timbl@w3.org" title="MIT, Laboratory for Computer Science">Berners-Lee, T.</a>, <a href="mailto:fielding@ics.uci.edu" title="University of California, Irvine, Department of Information and Computer Science">Fielding, R.</a>, and <a href="mailto:frystyk@w3.org" title="W3 Consortium, MIT Laboratory for Computer Science">H. Nielsen</a>, “<a href="http://tools.ietf.org/html/rfc1945">Hypertext Transfer Protocol -- HTTP/1.0</a>”, RFC 1945, May 1996. |
|---|
| 1585 | </td> |
|---|
| 1586 | </tr> |
|---|
| 1587 | <tr> |
|---|
| 1588 | <td class="reference"><b id="RFC2049">[RFC2049]</b></td> |
|---|
| 1589 | <td class="top"><a href="mailto:ned@innosoft.com" title="Innosoft International, Inc.">Freed, N.</a> and <a href="mailto:nsb@nsb.fv.com" title="First Virtual Holdings">N. Borenstein</a>, “<a href="http://tools.ietf.org/html/rfc2049">Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples</a>”, RFC 2049, November 1996. |
|---|
| 1590 | </td> |
|---|
| 1591 | </tr> |
|---|
| 1592 | <tr> |
|---|
| 1593 | <td class="reference"><b id="RFC2068">[RFC2068]</b></td> |
|---|
| 1594 | <td class="top"><a href="mailto:fielding@ics.uci.edu" title="University of California, Irvine, Department of Information and Computer Science">Fielding, R.</a>, <a href="mailto:jg@w3.org" title="MIT Laboratory for Computer Science">Gettys, J.</a>, <a href="mailto:mogul@wrl.dec.com" title="Digital Equipment Corporation, Western Research Laboratory">Mogul, J.</a>, <a href="mailto:frystyk@w3.org" title="MIT Laboratory for Computer Science">Nielsen, H.</a>, and <a href="mailto:timbl@w3.org" title="MIT Laboratory for Computer Science">T. Berners-Lee</a>, “<a href="http://tools.ietf.org/html/rfc2068">Hypertext Transfer Protocol -- HTTP/1.1</a>”, RFC 2068, January 1997. |
|---|
| 1595 | </td> |
|---|
| 1596 | </tr> |
|---|
| 1597 | <tr> |
|---|
| 1598 | <td class="reference"><b id="RFC2076">[RFC2076]</b></td> |
|---|
| 1599 | <td class="top"><a href="mailto:jpalme@dsv.su.se" title="Stockholm University/KTH">Palme, J.</a>, “<a href="http://tools.ietf.org/html/rfc2076">Common Internet Message Headers</a>”, RFC 2076, February 1997. |
|---|
| 1600 | </td> |
|---|
| 1601 | </tr> |
|---|
| 1602 | <tr> |
|---|
| 1603 | <td class="reference"><b id="RFC2277">[RFC2277]</b></td> |
|---|
| 1604 | <td class="top"><a href="mailto:Harald.T.Alvestrand@uninett.no" title="UNINETT">Alvestrand, H.</a>, “<a href="http://tools.ietf.org/html/rfc2277">IETF Policy on Character Sets and Languages</a>”, BCP 18, RFC 2277, January 1998. |
|---|
| 1605 | </td> |
|---|
| 1606 | </tr> |
|---|
| 1607 | <tr> |
|---|
| 1608 | <td class="reference"><b id="RFC2295">[RFC2295]</b></td> |
|---|
| 1609 | <td class="top"><a href="mailto:koen@win.tue.nl" title="Technische Universiteit Eindhoven">Holtman, K.</a> and <a href="mailto:mutz@hpl.hp.com" title="Hewlett-Packard Company">A. Mutz</a>, “<a href="http://tools.ietf.org/html/rfc2295">Transparent Content Negotiation in HTTP</a>”, RFC 2295, March 1998. |
|---|
| 1610 | </td> |
|---|
| 1611 | </tr> |
|---|
| 1612 | <tr> |
|---|
| 1613 | <td class="reference"><b id="RFC2388">[RFC2388]</b></td> |
|---|
| 1614 | <td class="top"><a href="mailto:masinter@parc.xerox.com" title="Xerox Palo Alto Research Center">Masinter, L.</a>, “<a href="http://tools.ietf.org/html/rfc2388">Returning Values from Forms: multipart/form-data</a>”, RFC 2388, August 1998. |
|---|
| 1615 | </td> |
|---|
| 1616 | </tr> |
|---|
| 1617 | <tr> |
|---|
| 1618 | <td class="reference"><b id="RFC2557">[RFC2557]</b></td> |
|---|
| 1619 | <td class="top"><a href="mailto:jpalme@dsv.su.se" title="Stockholm University and KTH">Palme, F.</a>, <a href="mailto:alexhop@microsoft.com" title="Microsoft Corporation">Hopmann, A.</a>, <a href="mailto:Shelness@lotus.com" title="Lotus Development Corporation">Shelness, N.</a>, and <a href="mailto:stef@nma.com">E. Stefferud</a>, “<a href="http://tools.ietf.org/html/rfc2557">MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)</a>”, RFC 2557, March 1999. |
|---|
| 1620 | </td> |
|---|
| 1621 | </tr> |
|---|
| 1622 | <tr> |
|---|
| 1623 | <td class="reference"><b id="RFC2616">[RFC2616]</b></td> |
|---|
| 1624 | <td class="top"><a href="mailto:fielding@ics.uci.edu" title="University of California, Irvine">Fielding, R.</a>, <a href="mailto:jg@w3.org" title="W3C">Gettys, J.</a>, <a href="mailto:mogul@wrl.dec.com" title="Compaq Computer Corporation">Mogul, J.</a>, <a href="mailto:frystyk@w3.org" title="MIT Laboratory for Computer Science">Frystyk, H.</a>, <a href="mailto:masinter@parc.xerox.com" title="Xerox Corporation">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com" title="Microsoft Corporation">Leach, P.</a>, and <a href="mailto:timbl@w3.org" title="W3C">T. Berners-Lee</a>, “<a href="http://tools.ietf.org/html/rfc2616">Hypertext Transfer Protocol -- HTTP/1.1</a>”, RFC 2616, June 1999. |
|---|
| 1625 | </td> |
|---|
| 1626 | </tr> |
|---|
| 1627 | <tr> |
|---|
| 1628 | <td class="reference"><b id="RFC3629">[RFC3629]</b></td> |
|---|
| 1629 | <td class="top"><a href="mailto:fyergeau@alis.com" title="Alis Technologies">Yergeau, F.</a>, “<a href="http://tools.ietf.org/html/rfc3629">UTF-8, a transformation format of ISO 10646</a>”, STD 63, RFC 3629, November 2003. |
|---|
| 1630 | </td> |
|---|
| 1631 | </tr> |
|---|
| 1632 | <tr> |
|---|
| 1633 | <td class="reference"><b id="RFC3864">[RFC3864]</b></td> |
|---|
| 1634 | <td class="top"><a href="mailto:GK-IETF@ninebynine.org" title="Nine by Nine">Klyne, G.</a>, <a href="mailto:mnot@pobox.com" title="BEA Systems">Nottingham, M.</a>, and <a href="mailto:JeffMogul@acm.org" title="HP Labs">J. Mogul</a>, “<a href="http://tools.ietf.org/html/rfc3864">Registration Procedures for Message Header Fields</a>”, BCP 90, RFC 3864, September 2004. |
|---|
| 1635 | </td> |
|---|
| 1636 | </tr> |
|---|
| 1637 | <tr> |
|---|
| 1638 | <td class="reference"><b id="RFC4288">[RFC4288]</b></td> |
|---|
| 1639 | <td class="top"><a href="mailto:ned.freed@mrochek.com" title="Sun Microsystems">Freed, N.</a> and <a href="mailto:klensin+ietf@jck.com">J. Klensin</a>, “<a href="http://tools.ietf.org/html/rfc4288">Media Type Specifications and Registration Procedures</a>”, BCP 13, RFC 4288, December 2005. |
|---|
| 1640 | </td> |
|---|
| 1641 | </tr> |
|---|
| 1642 | <tr> |
|---|
| 1643 | <td class="reference"><b id="RFC5226">[RFC5226]</b></td> |
|---|
| 1644 | <td class="top"><a href="mailto:narten@us.ibm.com" title="IBM">Narten, T.</a> and <a href="mailto:Harald@Alvestrand.no" title="Google">H. Alvestrand</a>, “<a href="http://tools.ietf.org/html/rfc5226">Guidelines for Writing an IANA Considerations Section in RFCs</a>”, BCP 26, RFC 5226, May 2008. |
|---|
| 1645 | </td> |
|---|
| 1646 | </tr> |
|---|
| 1647 | <tr> |
|---|
| 1648 | <td class="reference"><b id="RFC5322">[RFC5322]</b></td> |
|---|
| 1649 | <td class="top">Resnick, P., “<a href="http://tools.ietf.org/html/rfc5322">Internet Message Format</a>”, RFC 5322, October 2008. |
|---|
| 1650 | </td> |
|---|
| 1651 | </tr> |
|---|
| 1652 | <tr> |
|---|
| 1653 | <td class="reference"><b id="RFC6151">[RFC6151]</b></td> |
|---|
| 1654 | <td class="top">Turner, S. and L. Chen, “<a href="http://tools.ietf.org/html/rfc6151">Updated Security Considerations for the MD5 Message-Digest and the HMAC-MD5 Algorithms</a>”, RFC 6151, March 2011. |
|---|
| 1655 | </td> |
|---|
| 1656 | </tr> |
|---|
| 1657 | <tr> |
|---|
| 1658 | <td class="reference"><b id="RFC6266">[RFC6266]</b></td> |
|---|
| 1659 | <td class="top"><a href="mailto:julian.reschke@greenbytes.de" title="greenbytes GmbH">Reschke, J.</a>, “<a href="http://tools.ietf.org/html/rfc6266">Use of the Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)</a>”, RFC 6266, June 2011. |
|---|
| 1660 | </td> |
|---|
| 1661 | </tr> |
|---|
| 1662 | </table> |
|---|
| 1663 | <div class="avoidbreak"> |
|---|
| 1664 | <h1 id="rfc.authors"><a href="#rfc.authors">Authors' Addresses</a></h1> |
|---|
| 1665 | <address class="vcard"><span class="vcardline"><span class="fn">Roy T. Fielding</span> |
|---|
| 1666 | (editor) |
|---|
| 1667 | <span class="n hidden"><span class="family-name">Fielding</span><span class="given-name">Roy T.</span></span></span><span class="org vcardline">Adobe Systems Incorporated</span><span class="adr"><span class="street-address vcardline">345 Park Ave</span><span class="vcardline"><span class="locality">San Jose</span>, <span class="region">CA</span> <span class="postal-code">95110</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:fielding@gbiv.com"><span class="email">fielding@gbiv.com</span></a></span><span class="vcardline">URI: <a href="http://roy.gbiv.com/" class="url">http://roy.gbiv.com/</a></span></address> |
|---|
| 1668 | <address class="vcard"><span class="vcardline"><span class="fn">Jim Gettys</span><span class="n hidden"><span class="family-name">Gettys</span><span class="given-name">Jim</span></span></span><span class="org vcardline">Alcatel-Lucent Bell Labs</span><span class="adr"><span class="street-address vcardline">21 Oak Knoll Road</span><span class="vcardline"><span class="locality">Carlisle</span>, <span class="region">MA</span> <span class="postal-code">01741</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:jg@freedesktop.org"><span class="email">jg@freedesktop.org</span></a></span><span class="vcardline">URI: <a href="http://gettys.wordpress.com/" class="url">http://gettys.wordpress.com/</a></span></address> |
|---|
| 1669 | <address class="vcard"><span class="vcardline"><span class="fn">Jeffrey C. Mogul</span><span class="n hidden"><span class="family-name">Mogul</span><span class="given-name">Jeffrey C.</span></span></span><span class="org vcardline">Hewlett-Packard Company</span><span class="adr"><span class="street-address vcardline">HP Labs, Large Scale Systems Group</span><span class="street-address vcardline">1501 Page Mill Road, MS 1177</span><span class="vcardline"><span class="locality">Palo Alto</span>, <span class="region">CA</span> <span class="postal-code">94304</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:JeffMogul@acm.org"><span class="email">JeffMogul@acm.org</span></a></span></address> |
|---|
| 1670 | <address class="vcard"><span class="vcardline"><span class="fn">Henrik Frystyk Nielsen</span><span class="n hidden"><span class="family-name">Frystyk</span></span></span><span class="org vcardline">Microsoft Corporation</span><span class="adr"><span class="street-address vcardline">1 Microsoft Way</span><span class="vcardline"><span class="locality">Redmond</span>, <span class="region">WA</span> <span class="postal-code">98052</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:henrikn@microsoft.com"><span class="email">henrikn@microsoft.com</span></a></span></address> |
|---|
| 1671 | <address class="vcard"><span class="vcardline"><span class="fn">Larry Masinter</span><span class="n hidden"><span class="family-name">Masinter</span><span class="given-name">Larry</span></span></span><span class="org vcardline">Adobe Systems Incorporated</span><span class="adr"><span class="street-address vcardline">345 Park Ave</span><span class="vcardline"><span class="locality">San Jose</span>, <span class="region">CA</span> <span class="postal-code">95110</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:LMM@acm.org"><span class="email">LMM@acm.org</span></a></span><span class="vcardline">URI: <a href="http://larry.masinter.net/" class="url">http://larry.masinter.net/</a></span></address> |
|---|
| 1672 | <address class="vcard"><span class="vcardline"><span class="fn">Paul J. Leach</span><span class="n hidden"><span class="family-name">Leach</span><span class="given-name">Paul J.</span></span></span><span class="org vcardline">Microsoft Corporation</span><span class="adr"><span class="street-address vcardline">1 Microsoft Way</span><span class="vcardline"><span class="locality">Redmond</span>, <span class="region">WA</span> <span class="postal-code">98052</span></span></span><span class="vcardline">Email: <a href="mailto:paulle@microsoft.com"><span class="email">paulle@microsoft.com</span></a></span></address> |
|---|
| 1673 | <address class="vcard"><span class="vcardline"><span class="fn">Tim Berners-Lee</span><span class="n hidden"><span class="family-name">Berners-Lee</span><span class="given-name">Tim</span></span></span><span class="org vcardline">World Wide Web Consortium</span><span class="adr"><span class="street-address vcardline">MIT Computer Science and Artificial Intelligence Laboratory</span><span class="street-address vcardline">The Stata Center, Building 32</span><span class="street-address vcardline">32 Vassar Street</span><span class="vcardline"><span class="locality">Cambridge</span>, <span class="region">MA</span> <span class="postal-code">02139</span></span><span class="country-name vcardline">USA</span></span><span class="vcardline">Email: <a href="mailto:timbl@w3.org"><span class="email">timbl@w3.org</span></a></span><span class="vcardline">URI: <a href="http://www.w3.org/People/Berners-Lee/" class="url">http://www.w3.org/People/Berners-Lee/</a></span></address> |
|---|
| 1674 | <address class="vcard"><span class="vcardline"><span class="fn">Yves Lafon</span> |
|---|
| 1675 | (editor) |
|---|
| 1676 | <span class="n hidden"><span class="family-name">Lafon</span><span class="given-name">Yves</span></span></span><span class="org vcardline">World Wide Web Consortium</span><span class="adr"><span class="street-address vcardline">W3C / ERCIM</span><span class="street-address vcardline">2004, rte des Lucioles</span><span class="vcardline"><span class="locality">Sophia-Antipolis</span>, <span class="region">AM</span> <span class="postal-code">06902</span></span><span class="country-name vcardline">France</span></span><span class="vcardline">Email: <a href="mailto:ylafon@w3.org"><span class="email">ylafon@w3.org</span></a></span><span class="vcardline">URI: <a href="http://www.raubacapeu.net/people/yves/" class="url">http://www.raubacapeu.net/people/yves/</a></span></address> |
|---|
| 1677 | <address class="vcard"><span class="vcardline"><span class="fn">Julian F. Reschke</span> |
|---|
| 1678 | (editor) |
|---|
| 1679 | <span class="n hidden"><span class="family-name">Reschke</span><span class="given-name">Julian F.</span></span></span><span class="org vcardline">greenbytes GmbH</span><span class="adr"><span class="street-address vcardline">Hafenweg 16</span><span class="vcardline"><span class="locality">Muenster</span>, <span class="region">NW</span> <span class="postal-code">48155</span></span><span class="country-name vcardline">Germany</span></span><span class="vcardline tel">Phone: <a href="tel:+492512807760"><span class="value">+49 251 2807760</span></a></span><span class="vcardline tel"><span class="type">Fax</span>: <a href="fax:+492512807761"><span class="value">+49 251 2807761</span></a></span><span class="vcardline">Email: <a href="mailto:julian.reschke@greenbytes.de"><span class="email">julian.reschke@greenbytes.de</span></a></span><span class="vcardline">URI: <a href="http://greenbytes.de/tech/webdav/" class="url">http://greenbytes.de/tech/webdav/</a></span></address> |
|---|
| 1680 | </div> |
|---|
| 1681 | <h1 id="rfc.section.A" class="np"><a href="#rfc.section.A">A.</a> <a id="differences.between.http.and.mime" href="#differences.between.http.and.mime">Differences between HTTP and MIME</a></h1> |
|---|
| 1682 | <p id="rfc.section.A.p.1">HTTP/1.1 uses many of the constructs defined for Internet Mail (<a href="#RFC5322" id="rfc.xref.RFC5322.1"><cite title="Internet Message Format">[RFC5322]</cite></a>) and the Multipurpose Internet Mail Extensions (MIME <a href="#RFC2045" id="rfc.xref.RFC2045.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies">[RFC2045]</cite></a>) to allow a message-body to be transmitted in an open variety of representations and with extensible mechanisms. However, |
|---|
| 1683 | RFC 2045 discusses mail, and HTTP has a few features that are different from those described in MIME. These differences were |
|---|
| 1684 | carefully chosen to optimize performance over binary connections, to allow greater freedom in the use of new media types, |
|---|
| 1685 | to make date comparisons easier, and to acknowledge the practice of some early HTTP servers and clients. |
|---|
| 1686 | </p> |
|---|
| 1687 | <p id="rfc.section.A.p.2">This appendix describes specific areas where HTTP differs from MIME. Proxies and gateways to strict MIME environments <em class="bcp14">SHOULD</em> be aware of these differences and provide the appropriate conversions where necessary. Proxies and gateways from MIME environments |
|---|
| 1688 | to HTTP also need to be aware of the differences because some conversions might be required. |
|---|
| 1689 | </p> |
|---|
| 1690 | <div id="rfc.iref.m.1"></div> |
|---|
| 1691 | <div id="rfc.iref.h.9"></div> |
|---|
| 1692 | <h2 id="rfc.section.A.1"><a href="#rfc.section.A.1">A.1</a> <a id="mime-version" href="#mime-version">MIME-Version</a></h2> |
|---|
| 1693 | <p id="rfc.section.A.1.p.1">HTTP is not a MIME-compliant protocol. However, HTTP/1.1 messages <em class="bcp14">MAY</em> include a single MIME-Version header field to indicate what version of the MIME protocol was used to construct the message. |
|---|
| 1694 | Use of the MIME-Version header field indicates that the message is in full compliance with the MIME protocol (as defined in <a href="#RFC2045" id="rfc.xref.RFC2045.2"><cite title="Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies">[RFC2045]</cite></a>). Proxies/gateways are responsible for ensuring full compliance (where possible) when exporting HTTP messages to strict MIME |
|---|
| 1695 | environments. |
|---|
| 1696 | </p> |
|---|
| 1697 | <div id="rfc.figure.u.29"></div><pre class="inline"><span id="rfc.iref.g.24"></span> <a href="#mime-version" class="smpl">MIME-Version</a> = 1*<a href="#notation" class="smpl">DIGIT</a> "." 1*<a href="#notation" class="smpl">DIGIT</a> |
|---|
| 1698 | </pre><p id="rfc.section.A.1.p.3">MIME version "1.0" is the default for use in HTTP/1.1. However, HTTP/1.1 message parsing and semantics are defined by this |
|---|
| 1699 | document and not the MIME specification. |
|---|
| 1700 | </p> |
|---|
| 1701 | <h2 id="rfc.section.A.2"><a href="#rfc.section.A.2">A.2</a> <a id="conversion.to.canonical.form" href="#conversion.to.canonical.form">Conversion to Canonical Form</a></h2> |
|---|
| 1702 | <p id="rfc.section.A.2.p.1">MIME requires that an Internet mail body-part be converted to canonical form prior to being transferred, as described in <a href="http://tools.ietf.org/html/rfc2049#section-4">Section 4</a> of <a href="#RFC2049" id="rfc.xref.RFC2049.1"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples">[RFC2049]</cite></a>. <a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 2.3.1</a> of this document describes the forms allowed for subtypes of the "text" media type when transmitted over HTTP. <a href="#RFC2046" id="rfc.xref.RFC2046.4"><cite title="Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types">[RFC2046]</cite></a> requires that content with a type of "text" represent line breaks as CRLF and forbids the use of CR or LF outside of line |
|---|
| 1703 | break sequences. HTTP allows CRLF, bare CR, and bare LF to indicate a line break within text content when a message is transmitted |
|---|
| 1704 | over HTTP. |
|---|
| 1705 | </p> |
|---|
| 1706 | <p id="rfc.section.A.2.p.2">Where it is possible, a proxy or gateway from HTTP to a strict MIME environment <em class="bcp14">SHOULD</em> translate all line breaks within the text media types described in <a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 2.3.1</a> of this document to the RFC 2049 canonical form of CRLF. Note, however, that this might be complicated by the presence of |
|---|
| 1707 | a Content-Encoding and by the fact that HTTP allows the use of some character encodings which do not use octets 13 and 10 |
|---|
| 1708 | to represent CR and LF, respectively, as is the case for some multi-byte character encodings. |
|---|
| 1709 | </p> |
|---|
| 1710 | <p id="rfc.section.A.2.p.3">Conversion will break any cryptographic checksums applied to the original content unless the original content is already in |
|---|
| 1711 | canonical form. Therefore, the canonical form is recommended for any content that uses such checksums in HTTP. |
|---|
| 1712 | </p> |
|---|
| 1713 | <h2 id="rfc.section.A.3"><a href="#rfc.section.A.3">A.3</a> <a id="conversion.of.date.formats" href="#conversion.of.date.formats">Conversion of Date Formats</a></h2> |
|---|
| 1714 | <p id="rfc.section.A.3.p.1">HTTP/1.1 uses a restricted set of date formats (<a href="p2-semantics.html#http.date" title="Date/Time Formats">Section 8</a> of <a href="#Part2" id="rfc.xref.Part2.2"><cite title="HTTP/1.1, part 2: Message Semantics">[Part2]</cite></a>) to simplify the process of date comparison. Proxies and gateways from other protocols <em class="bcp14">SHOULD</em> ensure that any Date header field present in a message conforms to one of the HTTP/1.1 formats and rewrite the date if necessary. |
|---|
| 1715 | </p> |
|---|
| 1716 | <h2 id="rfc.section.A.4"><a href="#rfc.section.A.4">A.4</a> <a id="introduction.of.content-encoding" href="#introduction.of.content-encoding">Introduction of Content-Encoding</a></h2> |
|---|
| 1717 | <p id="rfc.section.A.4.p.1">MIME does not include any concept equivalent to HTTP/1.1's Content-Encoding header field. Since this acts as a modifier on |
|---|
| 1718 | the media type, proxies and gateways from HTTP to MIME-compliant protocols <em class="bcp14">MUST</em> either change the value of the Content-Type header field or decode the representation before forwarding the message. (Some |
|---|
| 1719 | experimental applications of Content-Type for Internet mail have used a media-type parameter of ";conversions=<content-coding>" |
|---|
| 1720 | to perform a function equivalent to Content-Encoding. However, this parameter is not part of the MIME standards). |
|---|
| 1721 | </p> |
|---|
| 1722 | <h2 id="rfc.section.A.5"><a href="#rfc.section.A.5">A.5</a> <a id="no.content-transfer-encoding" href="#no.content-transfer-encoding">No Content-Transfer-Encoding</a></h2> |
|---|
| 1723 | <p id="rfc.section.A.5.p.1">HTTP does not use the Content-Transfer-Encoding field of MIME. Proxies and gateways from MIME-compliant protocols to HTTP <em class="bcp14">MUST</em> remove any Content-Transfer-Encoding prior to delivering the response message to an HTTP client. |
|---|
| 1724 | </p> |
|---|
| 1725 | <p id="rfc.section.A.5.p.2">Proxies and gateways from HTTP to MIME-compliant protocols are responsible for ensuring that the message is in the correct |
|---|
| 1726 | format and encoding for safe transport on that protocol, where "safe transport" is defined by the limitations of the protocol |
|---|
| 1727 | being used. Such a proxy or gateway <em class="bcp14">SHOULD</em> label the data with an appropriate Content-Transfer-Encoding if doing so will improve the likelihood of safe transport over |
|---|
| 1728 | the destination protocol. |
|---|
| 1729 | </p> |
|---|
| 1730 | <h2 id="rfc.section.A.6"><a href="#rfc.section.A.6">A.6</a> <a id="introduction.of.transfer-encoding" href="#introduction.of.transfer-encoding">Introduction of Transfer-Encoding</a></h2> |
|---|
| 1731 | <p id="rfc.section.A.6.p.1">HTTP/1.1 introduces the Transfer-Encoding header field (<a href="p1-messaging.html#header.transfer-encoding" title="Transfer-Encoding">Section 8.6</a> of <a href="#Part1" id="rfc.xref.Part1.25"><cite title="HTTP/1.1, part 1: URIs, Connections, and Message Parsing">[Part1]</cite></a>). Proxies/gateways <em class="bcp14">MUST</em> remove any transfer-coding prior to forwarding a message via a MIME-compliant protocol. |
|---|
| 1732 | </p> |
|---|
| 1733 | <h2 id="rfc.section.A.7"><a href="#rfc.section.A.7">A.7</a> <a id="mhtml.line.length" href="#mhtml.line.length">MHTML and Line Length Limitations</a></h2> |
|---|
| 1734 | <p id="rfc.section.A.7.p.1">HTTP implementations which share code with MHTML <a href="#RFC2557" id="rfc.xref.RFC2557.2"><cite title="MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)">[RFC2557]</cite></a> implementations need to be aware of MIME line length limitations. Since HTTP does not have this limitation, HTTP does not |
|---|
| 1735 | fold long lines. MHTML messages being transported by HTTP follow all conventions of MHTML, including line length limitations |
|---|
| 1736 | and folding, canonicalization, etc., since HTTP transports all message-bodies as payload (see <a href="#multipart.types" title="Multipart Types">Section 2.3.2</a>) and does not interpret the content or any MIME header lines that might be contained therein. |
|---|
| 1737 | </p> |
|---|
| 1738 | <h1 id="rfc.section.B"><a href="#rfc.section.B">B.</a> <a id="additional.features" href="#additional.features">Additional Features</a></h1> |
|---|
| 1739 | <p id="rfc.section.B.p.1"> <a href="#RFC1945" id="rfc.xref.RFC1945.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.0">[RFC1945]</cite></a> and <a href="#RFC2068" id="rfc.xref.RFC2068.4"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2068]</cite></a> document protocol elements used by some existing HTTP implementations, but not consistently and correctly across most HTTP/1.1 |
|---|
| 1740 | applications. Implementors are advised to be aware of these features, but cannot rely upon their presence in, or interoperability |
|---|
| 1741 | with, other HTTP/1.1 applications. Some of these describe proposed experimental features, and some describe features that |
|---|
| 1742 | experimental deployment found lacking that are now addressed in the base HTTP/1.1 specification. |
|---|
| 1743 | </p> |
|---|
| 1744 | <p id="rfc.section.B.p.2">A number of other header fields, such as Content-Disposition and Title, from SMTP and MIME are also often implemented (see <a href="#RFC6266" id="rfc.xref.RFC6266.1"><cite title="Use of the Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)">[RFC6266]</cite></a> and <a href="#RFC2076" id="rfc.xref.RFC2076.1"><cite title="Common Internet Message Headers">[RFC2076]</cite></a>). |
|---|
| 1745 | </p> |
|---|
| 1746 | <h1 id="rfc.section.C"><a href="#rfc.section.C">C.</a> <a id="changes.from.rfc.2616" href="#changes.from.rfc.2616">Changes from RFC 2616</a></h1> |
|---|
| 1747 | <p id="rfc.section.C.p.1">Clarify contexts that charset is used in. (<a href="#character.sets" title="Character Encodings (charset)">Section 2.1</a>) |
|---|
| 1748 | </p> |
|---|
| 1749 | <p id="rfc.section.C.p.2">Remove the default character encoding for text media types; the default now is whatever the media type definition says. (<a href="#canonicalization.and.text.defaults" title="Canonicalization and Text Defaults">Section 2.3.1</a>) |
|---|
| 1750 | </p> |
|---|
| 1751 | <p id="rfc.section.C.p.3">Change ABNF productions for header fields to only define the field value. (<a href="#header.field.definitions" title="Header Field Definitions">Section 6</a>) |
|---|
| 1752 | </p> |
|---|
| 1753 | <p id="rfc.section.C.p.4">Remove definition of Content-MD5 header field because it was inconsistently implemented with respect to partial responses, |
|---|
| 1754 | and also because of known deficiencies in the hash algorithm itself (see <a href="#RFC6151" id="rfc.xref.RFC6151.1"><cite title="Updated Security Considerations for the MD5 Message-Digest and the HMAC-MD5 Algorithms">[RFC6151]</cite></a> for details). (<a href="#header.field.definitions" title="Header Field Definitions">Section 6</a>) |
|---|
| 1755 | </p> |
|---|
| 1756 | <p id="rfc.section.C.p.5">Remove ISO-8859-1 special-casing in Accept-Charset. (<a href="#header.accept-charset" id="rfc.xref.header.accept-charset.3" title="Accept-Charset">Section 6.2</a>) |
|---|
| 1757 | </p> |
|---|
| 1758 | <p id="rfc.section.C.p.6">Remove base URI setting semantics for Content-Location due to poor implementation support, which was caused by too many broken |
|---|
| 1759 | servers emitting bogus Content-Location header fields, and also the potentially undesirable effect of potentially breaking |
|---|
| 1760 | relative links in content-negotiated resources. (<a href="#header.content-location" id="rfc.xref.header.content-location.3" title="Content-Location">Section 6.7</a>) |
|---|
| 1761 | </p> |
|---|
| 1762 | <p id="rfc.section.C.p.7">Remove discussion of Content-Disposition header field, it is now defined by <a href="#RFC6266" id="rfc.xref.RFC6266.2"><cite title="Use of the Content-Disposition Header Field in the Hypertext Transfer Protocol (HTTP)">[RFC6266]</cite></a>. (<a href="#additional.features" title="Additional Features">Appendix B</a>) |
|---|
| 1763 | </p> |
|---|
| 1764 | <p id="rfc.section.C.p.8">Remove reference to non-existant identity transfer-coding value tokens. (<a href="#no.content-transfer-encoding" title="No Content-Transfer-Encoding">Appendix A.5</a>) |
|---|
| 1765 | </p> |
|---|
| 1766 | <h1 id="rfc.section.D"><a href="#rfc.section.D">D.</a> <a id="collected.abnf" href="#collected.abnf">Collected ABNF</a></h1> |
|---|
| 1767 | <div id="rfc.figure.u.30"></div> <pre class="inline"><a href="#header.accept" class="smpl">Accept</a> = [ ( "," / ( media-range [ accept-params ] ) ) *( OWS "," [ |
|---|
| 1768 | OWS media-range [ accept-params ] ] ) ] |
|---|
| 1769 | <a href="#header.accept-charset" class="smpl">Accept-Charset</a> = *( "," OWS ) ( charset / "*" ) [ OWS ";" OWS "q=" |
|---|
| 1770 | qvalue ] *( OWS "," [ OWS ( charset / "*" ) [ OWS ";" OWS "q=" |
|---|
| 1771 | qvalue ] ] ) |
|---|
| 1772 | <a href="#header.accept-encoding" class="smpl">Accept-Encoding</a> = [ ( "," / ( codings [ OWS ";" OWS "q=" qvalue ] ) ) |
|---|
| 1773 | *( OWS "," [ OWS codings [ OWS ";" OWS "q=" qvalue ] ] ) ] |
|---|
| 1774 | <a href="#header.accept-language" class="smpl">Accept-Language</a> = *( "," OWS ) language-range [ OWS ";" OWS "q=" |
|---|
| 1775 | qvalue ] *( OWS "," [ OWS language-range [ OWS ";" OWS "q=" qvalue ] |
|---|
| 1776 | ] ) |
|---|
| 1777 | |
|---|
| 1778 | <a href="#header.content-encoding" class="smpl">Content-Encoding</a> = *( "," OWS ) content-coding *( OWS "," [ OWS |
|---|
| 1779 | content-coding ] ) |
|---|
| 1780 | <a href="#header.content-language" class="smpl">Content-Language</a> = *( "," OWS ) language-tag *( OWS "," [ OWS |
|---|
| 1781 | language-tag ] ) |
|---|
| 1782 | <a href="#header.content-location" class="smpl">Content-Location</a> = absolute-URI / partial-URI |
|---|
| 1783 | <a href="#header.content-type" class="smpl">Content-Type</a> = media-type |
|---|
| 1784 | |
|---|
| 1785 | <a href="#mime-version" class="smpl">MIME-Version</a> = 1*DIGIT "." 1*DIGIT |
|---|
| 1786 | |
|---|
| 1787 | <a href="#core.rules" class="smpl">OWS</a> = <OWS, defined in [Part1], Section 1.2.2> |
|---|
| 1788 | |
|---|
| 1789 | <a href="#abnf.dependencies" class="smpl">absolute-URI</a> = <absolute-URI, defined in [Part1], Section 2.7> |
|---|
| 1790 | <a href="#header.accept" class="smpl">accept-ext</a> = OWS ";" OWS token [ "=" word ] |
|---|
| 1791 | <a href="#header.accept" class="smpl">accept-params</a> = OWS ";" OWS "q=" qvalue *accept-ext |
|---|
| 1792 | <a href="#rule.parameter" class="smpl">attribute</a> = token |
|---|
| 1793 | |
|---|
| 1794 | <a href="#rule.charset" class="smpl">charset</a> = token |
|---|
| 1795 | <a href="#header.accept-encoding" class="smpl">codings</a> = content-coding / "identity" / "*" |
|---|
| 1796 | <a href="#content.codings" class="smpl">content-coding</a> = token |
|---|
| 1797 | |
|---|
| 1798 | <a href="#header.accept-language" class="smpl">language-range</a> = <language-range, defined in [RFC4647], Section 2.1> |
|---|
| 1799 | <a href="#language.tags" class="smpl">language-tag</a> = <Language-Tag, defined in [RFC5646], Section 2.1> |
|---|
| 1800 | |
|---|
| 1801 | <a href="#header.accept" class="smpl">media-range</a> = ( "*/*" / ( type "/*" ) / ( type "/" subtype ) ) *( OWS |
|---|
| 1802 | ";" OWS parameter ) |
|---|
| 1803 | <a href="#media.types" class="smpl">media-type</a> = type "/" subtype *( OWS ";" OWS parameter ) |
|---|
| 1804 | |
|---|
| 1805 | <a href="#rule.parameter" class="smpl">parameter</a> = attribute "=" value |
|---|
| 1806 | <a href="#abnf.dependencies" class="smpl">partial-URI</a> = <partial-URI, defined in [Part1], Section 2.7> |
|---|
| 1807 | |
|---|
| 1808 | <a href="#abnf.dependencies" class="smpl">qvalue</a> = <qvalue, defined in [Part1], Section 5.3> |
|---|
| 1809 | |
|---|
| 1810 | <a href="#media.types" class="smpl">subtype</a> = token |
|---|
| 1811 | |
|---|
| 1812 | <a href="#core.rules" class="smpl">token</a> = <token, defined in [Part1], Section 3.2.3> |
|---|
| 1813 | <a href="#media.types" class="smpl">type</a> = token |
|---|
| 1814 | |
|---|
| 1815 | <a href="#rule.parameter" class="smpl">value</a> = word |
|---|
| 1816 | |
|---|
| 1817 | <a href="#core.rules" class="smpl">word</a> = <word, defined in [Part1], Section 3.2.3> |
|---|
| 1818 | </pre> <div id="rfc.figure.u.31"></div> |
|---|
| 1819 | <p>ABNF diagnostics:</p><pre class="inline">; Accept defined but not used |
|---|
| 1820 | ; Accept-Charset defined but not used |
|---|
| 1821 | ; Accept-Encoding defined but not used |
|---|
| 1822 | ; Accept-Language defined but not used |
|---|
| 1823 | ; Content-Encoding defined but not used |
|---|
| 1824 | ; Content-Language defined but not used |
|---|
| 1825 | ; Content-Location defined but not used |
|---|
| 1826 | ; Content-Type defined but not used |
|---|
| 1827 | ; MIME-Version defined but not used |
|---|
| 1828 | </pre><h1 id="rfc.section.E"><a href="#rfc.section.E">E.</a> <a id="change.log" href="#change.log">Change Log (to be removed by RFC Editor before publication)</a></h1> |
|---|
| 1829 | <h2 id="rfc.section.E.1"><a href="#rfc.section.E.1">E.1</a> Since RFC 2616 |
|---|
| 1830 | </h2> |
|---|
| 1831 | <p id="rfc.section.E.1.p.1">Extracted relevant partitions from <a href="#RFC2616" id="rfc.xref.RFC2616.3"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>. |
|---|
| 1832 | </p> |
|---|
| 1833 | <h2 id="rfc.section.E.2"><a href="#rfc.section.E.2">E.2</a> Since draft-ietf-httpbis-p3-payload-00 |
|---|
| 1834 | </h2> |
|---|
| 1835 | <p id="rfc.section.E.2.p.1">Closed issues: </p> |
|---|
| 1836 | <ul> |
|---|
| 1837 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/8">http://tools.ietf.org/wg/httpbis/trac/ticket/8</a>>: "Media Type Registrations" (<<a href="http://purl.org/NET/http-errata#media-reg">http://purl.org/NET/http-errata#media-reg</a>>) |
|---|
| 1838 | </li> |
|---|
| 1839 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/14">http://tools.ietf.org/wg/httpbis/trac/ticket/14</a>>: "Clarification regarding quoting of charset values" (<<a href="http://purl.org/NET/http-errata#charactersets">http://purl.org/NET/http-errata#charactersets</a>>) |
|---|
| 1840 | </li> |
|---|
| 1841 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/16">http://tools.ietf.org/wg/httpbis/trac/ticket/16</a>>: "Remove 'identity' token references" (<<a href="http://purl.org/NET/http-errata#identity">http://purl.org/NET/http-errata#identity</a>>) |
|---|
| 1842 | </li> |
|---|
| 1843 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/25">http://tools.ietf.org/wg/httpbis/trac/ticket/25</a>>: "Accept-Encoding BNF" |
|---|
| 1844 | </li> |
|---|
| 1845 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/35">http://tools.ietf.org/wg/httpbis/trac/ticket/35</a>>: "Normative and Informative references" |
|---|
| 1846 | </li> |
|---|
| 1847 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/46">http://tools.ietf.org/wg/httpbis/trac/ticket/46</a>>: "RFC1700 references" |
|---|
| 1848 | </li> |
|---|
| 1849 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/55">http://tools.ietf.org/wg/httpbis/trac/ticket/55</a>>: "Updating to RFC4288" |
|---|
| 1850 | </li> |
|---|
| 1851 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/65">http://tools.ietf.org/wg/httpbis/trac/ticket/65</a>>: "Informative references" |
|---|
| 1852 | </li> |
|---|
| 1853 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/66">http://tools.ietf.org/wg/httpbis/trac/ticket/66</a>>: "ISO-8859-1 Reference" |
|---|
| 1854 | </li> |
|---|
| 1855 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/68">http://tools.ietf.org/wg/httpbis/trac/ticket/68</a>>: "Encoding References Normative" |
|---|
| 1856 | </li> |
|---|
| 1857 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/86">http://tools.ietf.org/wg/httpbis/trac/ticket/86</a>>: "Normative up-to-date references" |
|---|
| 1858 | </li> |
|---|
| 1859 | </ul> |
|---|
| 1860 | <h2 id="rfc.section.E.3"><a href="#rfc.section.E.3">E.3</a> Since draft-ietf-httpbis-p3-payload-01 |
|---|
| 1861 | </h2> |
|---|
| 1862 | <p id="rfc.section.E.3.p.1">Ongoing work on ABNF conversion (<<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/36">http://tools.ietf.org/wg/httpbis/trac/ticket/36</a>>): |
|---|
| 1863 | </p> |
|---|
| 1864 | <ul> |
|---|
| 1865 | <li>Add explicit references to BNF syntax and rules imported from other parts of the specification.</li> |
|---|
| 1866 | </ul> |
|---|
| 1867 | <h2 id="rfc.section.E.4"><a href="#rfc.section.E.4">E.4</a> <a id="changes.since.02" href="#changes.since.02">Since draft-ietf-httpbis-p3-payload-02</a></h2> |
|---|
| 1868 | <p id="rfc.section.E.4.p.1">Closed issues: </p> |
|---|
| 1869 | <ul> |
|---|
| 1870 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/67">http://tools.ietf.org/wg/httpbis/trac/ticket/67</a>>: "Quoting Charsets" |
|---|
| 1871 | </li> |
|---|
| 1872 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/105">http://tools.ietf.org/wg/httpbis/trac/ticket/105</a>>: "Classification for Allow header" |
|---|
| 1873 | </li> |
|---|
| 1874 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/115">http://tools.ietf.org/wg/httpbis/trac/ticket/115</a>>: "missing default for qvalue in description of Accept-Encoding" |
|---|
| 1875 | </li> |
|---|
| 1876 | </ul> |
|---|
| 1877 | <p id="rfc.section.E.4.p.2">Ongoing work on IANA Message Header Field Registration (<<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/40">http://tools.ietf.org/wg/httpbis/trac/ticket/40</a>>): |
|---|
| 1878 | </p> |
|---|
| 1879 | <ul> |
|---|
| 1880 | <li>Reference RFC 3984, and update header field registrations for headers defined in this document.</li> |
|---|
| 1881 | </ul> |
|---|
| 1882 | <h2 id="rfc.section.E.5"><a href="#rfc.section.E.5">E.5</a> <a id="changes.since.03" href="#changes.since.03">Since draft-ietf-httpbis-p3-payload-03</a></h2> |
|---|
| 1883 | <p id="rfc.section.E.5.p.1">Closed issues: </p> |
|---|
| 1884 | <ul> |
|---|
| 1885 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/67">http://tools.ietf.org/wg/httpbis/trac/ticket/67</a>>: "Quoting Charsets" |
|---|
| 1886 | </li> |
|---|
| 1887 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/113">http://tools.ietf.org/wg/httpbis/trac/ticket/113</a>>: "language tag matching (Accept-Language) vs RFC4647" |
|---|
| 1888 | </li> |
|---|
| 1889 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/121">http://tools.ietf.org/wg/httpbis/trac/ticket/121</a>>: "RFC 1806 has been replaced by RFC2183" |
|---|
| 1890 | </li> |
|---|
| 1891 | </ul> |
|---|
| 1892 | <p id="rfc.section.E.5.p.2">Other changes: </p> |
|---|
| 1893 | <ul> |
|---|
| 1894 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/68">http://tools.ietf.org/wg/httpbis/trac/ticket/68</a>>: "Encoding References Normative" — rephrase the annotation and reference <a href="#BCP97" id="rfc.xref.BCP97.4"><cite title="Handling Normative References to Standards-Track Documents">[BCP97]</cite></a>. |
|---|
| 1895 | </li> |
|---|
| 1896 | </ul> |
|---|
| 1897 | <h2 id="rfc.section.E.6"><a href="#rfc.section.E.6">E.6</a> <a id="changes.since.04" href="#changes.since.04">Since draft-ietf-httpbis-p3-payload-04</a></h2> |
|---|
| 1898 | <p id="rfc.section.E.6.p.1">Closed issues: </p> |
|---|
| 1899 | <ul> |
|---|
| 1900 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/132">http://tools.ietf.org/wg/httpbis/trac/ticket/132</a>>: "RFC 2822 is updated by RFC 5322" |
|---|
| 1901 | </li> |
|---|
| 1902 | </ul> |
|---|
| 1903 | <p id="rfc.section.E.6.p.2">Ongoing work on ABNF conversion (<<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/36">http://tools.ietf.org/wg/httpbis/trac/ticket/36</a>>): |
|---|
| 1904 | </p> |
|---|
| 1905 | <ul> |
|---|
| 1906 | <li>Use "/" instead of "|" for alternatives.</li> |
|---|
| 1907 | <li>Introduce new ABNF rules for "bad" whitespace ("BWS"), optional whitespace ("OWS") and required whitespace ("RWS").</li> |
|---|
| 1908 | <li>Rewrite ABNFs to spell out whitespace rules, factor out header field value format definitions.</li> |
|---|
| 1909 | </ul> |
|---|
| 1910 | <h2 id="rfc.section.E.7"><a href="#rfc.section.E.7">E.7</a> <a id="changes.since.05" href="#changes.since.05">Since draft-ietf-httpbis-p3-payload-05</a></h2> |
|---|
| 1911 | <p id="rfc.section.E.7.p.1">Closed issues: </p> |
|---|
| 1912 | <ul> |
|---|
| 1913 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/118">http://tools.ietf.org/wg/httpbis/trac/ticket/118</a>>: "Join "Differences Between HTTP Entities and RFC 2045 Entities"?" |
|---|
| 1914 | </li> |
|---|
| 1915 | </ul> |
|---|
| 1916 | <p id="rfc.section.E.7.p.2">Final work on ABNF conversion (<<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/36">http://tools.ietf.org/wg/httpbis/trac/ticket/36</a>>): |
|---|
| 1917 | </p> |
|---|
| 1918 | <ul> |
|---|
| 1919 | <li>Add appendix containing collected and expanded ABNF, reorganize ABNF introduction.</li> |
|---|
| 1920 | </ul> |
|---|
| 1921 | <p id="rfc.section.E.7.p.3">Other changes: </p> |
|---|
| 1922 | <ul> |
|---|
| 1923 | <li>Move definition of quality values into Part 1.</li> |
|---|
| 1924 | </ul> |
|---|
| 1925 | <h2 id="rfc.section.E.8"><a href="#rfc.section.E.8">E.8</a> <a id="changes.since.06" href="#changes.since.06">Since draft-ietf-httpbis-p3-payload-06</a></h2> |
|---|
| 1926 | <p id="rfc.section.E.8.p.1">Closed issues: </p> |
|---|
| 1927 | <ul> |
|---|
| 1928 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/80">http://tools.ietf.org/wg/httpbis/trac/ticket/80</a>>: "Content-Location isn't special" |
|---|
| 1929 | </li> |
|---|
| 1930 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/155">http://tools.ietf.org/wg/httpbis/trac/ticket/155</a>>: "Content Sniffing" |
|---|
| 1931 | </li> |
|---|
| 1932 | </ul> |
|---|
| 1933 | <h2 id="rfc.section.E.9"><a href="#rfc.section.E.9">E.9</a> <a id="changes.since.07" href="#changes.since.07">Since draft-ietf-httpbis-p3-payload-07</a></h2> |
|---|
| 1934 | <p id="rfc.section.E.9.p.1">Closed issues: </p> |
|---|
| 1935 | <ul> |
|---|
| 1936 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/13">http://tools.ietf.org/wg/httpbis/trac/ticket/13</a>>: "Updated reference for language tags" |
|---|
| 1937 | </li> |
|---|
| 1938 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/110">http://tools.ietf.org/wg/httpbis/trac/ticket/110</a>>: "Clarify rules for determining what entities a response carries" |
|---|
| 1939 | </li> |
|---|
| 1940 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/154">http://tools.ietf.org/wg/httpbis/trac/ticket/154</a>>: "Content-Location base-setting problems" |
|---|
| 1941 | </li> |
|---|
| 1942 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/155">http://tools.ietf.org/wg/httpbis/trac/ticket/155</a>>: "Content Sniffing" |
|---|
| 1943 | </li> |
|---|
| 1944 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/188">http://tools.ietf.org/wg/httpbis/trac/ticket/188</a>>: "pick IANA policy (RFC5226) for Transfer Coding / Content Coding" |
|---|
| 1945 | </li> |
|---|
| 1946 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/189">http://tools.ietf.org/wg/httpbis/trac/ticket/189</a>>: "move definitions of gzip/deflate/compress to part 1" |
|---|
| 1947 | </li> |
|---|
| 1948 | </ul> |
|---|
| 1949 | <p id="rfc.section.E.9.p.2">Partly resolved issues: </p> |
|---|
| 1950 | <ul> |
|---|
| 1951 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/148">http://tools.ietf.org/wg/httpbis/trac/ticket/148</a>>: "update IANA requirements wrt Transfer-Coding values" (add the IANA Considerations subsection) |
|---|
| 1952 | </li> |
|---|
| 1953 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/149">http://tools.ietf.org/wg/httpbis/trac/ticket/149</a>>: "update IANA requirements wrt Content-Coding values" (add the IANA Considerations subsection) |
|---|
| 1954 | </li> |
|---|
| 1955 | </ul> |
|---|
| 1956 | <h2 id="rfc.section.E.10"><a href="#rfc.section.E.10">E.10</a> <a id="changes.since.08" href="#changes.since.08">Since draft-ietf-httpbis-p3-payload-08</a></h2> |
|---|
| 1957 | <p id="rfc.section.E.10.p.1">Closed issues: </p> |
|---|
| 1958 | <ul> |
|---|
| 1959 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/81">http://tools.ietf.org/wg/httpbis/trac/ticket/81</a>>: "Content Negotiation for media types" |
|---|
| 1960 | </li> |
|---|
| 1961 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/181">http://tools.ietf.org/wg/httpbis/trac/ticket/181</a>>: "Accept-Language: which RFC4647 filtering?" |
|---|
| 1962 | </li> |
|---|
| 1963 | </ul> |
|---|
| 1964 | <h2 id="rfc.section.E.11"><a href="#rfc.section.E.11">E.11</a> <a id="changes.since.09" href="#changes.since.09">Since draft-ietf-httpbis-p3-payload-09</a></h2> |
|---|
| 1965 | <p id="rfc.section.E.11.p.1">Closed issues: </p> |
|---|
| 1966 | <ul> |
|---|
| 1967 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/122">http://tools.ietf.org/wg/httpbis/trac/ticket/122</a>>: "MIME-Version not listed in P1, general header fields" |
|---|
| 1968 | </li> |
|---|
| 1969 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/143">http://tools.ietf.org/wg/httpbis/trac/ticket/143</a>>: "IANA registry for content/transfer encodings" |
|---|
| 1970 | </li> |
|---|
| 1971 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/155">http://tools.ietf.org/wg/httpbis/trac/ticket/155</a>>: "Content Sniffing" |
|---|
| 1972 | </li> |
|---|
| 1973 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/200">http://tools.ietf.org/wg/httpbis/trac/ticket/200</a>>: "use of term "word" when talking about header structure" |
|---|
| 1974 | </li> |
|---|
| 1975 | </ul> |
|---|
| 1976 | <p id="rfc.section.E.11.p.2">Partly resolved issues: </p> |
|---|
| 1977 | <ul> |
|---|
| 1978 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/196">http://tools.ietf.org/wg/httpbis/trac/ticket/196</a>>: "Term for the requested resource's URI" |
|---|
| 1979 | </li> |
|---|
| 1980 | </ul> |
|---|
| 1981 | <h2 id="rfc.section.E.12"><a href="#rfc.section.E.12">E.12</a> <a id="changes.since.10" href="#changes.since.10">Since draft-ietf-httpbis-p3-payload-10</a></h2> |
|---|
| 1982 | <p id="rfc.section.E.12.p.1">Closed issues: </p> |
|---|
| 1983 | <ul> |
|---|
| 1984 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/69">http://tools.ietf.org/wg/httpbis/trac/ticket/69</a>>: "Clarify 'Requested Variant'" |
|---|
| 1985 | </li> |
|---|
| 1986 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/80">http://tools.ietf.org/wg/httpbis/trac/ticket/80</a>>: "Content-Location isn't special" |
|---|
| 1987 | </li> |
|---|
| 1988 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/90">http://tools.ietf.org/wg/httpbis/trac/ticket/90</a>>: "Delimiting messages with multipart/byteranges" |
|---|
| 1989 | </li> |
|---|
| 1990 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/109">http://tools.ietf.org/wg/httpbis/trac/ticket/109</a>>: "Clarify entity / representation / variant terminology" |
|---|
| 1991 | </li> |
|---|
| 1992 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/136">http://tools.ietf.org/wg/httpbis/trac/ticket/136</a>>: "confusing req. language for Content-Location" |
|---|
| 1993 | </li> |
|---|
| 1994 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/167">http://tools.ietf.org/wg/httpbis/trac/ticket/167</a>>: "Content-Location on 304 responses" |
|---|
| 1995 | </li> |
|---|
| 1996 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/183">http://tools.ietf.org/wg/httpbis/trac/ticket/183</a>>: "'requested resource' in content-encoding definition" |
|---|
| 1997 | </li> |
|---|
| 1998 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/220">http://tools.ietf.org/wg/httpbis/trac/ticket/220</a>>: "consider removing the 'changes from 2068' sections" |
|---|
| 1999 | </li> |
|---|
| 2000 | </ul> |
|---|
| 2001 | <p id="rfc.section.E.12.p.2">Partly resolved issues: </p> |
|---|
| 2002 | <ul> |
|---|
| 2003 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/178">http://tools.ietf.org/wg/httpbis/trac/ticket/178</a>>: "Content-MD5 and partial responses" |
|---|
| 2004 | </li> |
|---|
| 2005 | </ul> |
|---|
| 2006 | <h2 id="rfc.section.E.13"><a href="#rfc.section.E.13">E.13</a> <a id="changes.since.11" href="#changes.since.11">Since draft-ietf-httpbis-p3-payload-11</a></h2> |
|---|
| 2007 | <p id="rfc.section.E.13.p.1">Closed issues: </p> |
|---|
| 2008 | <ul> |
|---|
| 2009 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/123">http://tools.ietf.org/wg/httpbis/trac/ticket/123</a>>: "Factor out Content-Disposition" |
|---|
| 2010 | </li> |
|---|
| 2011 | </ul> |
|---|
| 2012 | <h2 id="rfc.section.E.14"><a href="#rfc.section.E.14">E.14</a> <a id="changes.since.12" href="#changes.since.12">Since draft-ietf-httpbis-p3-payload-12</a></h2> |
|---|
| 2013 | <p id="rfc.section.E.14.p.1">Closed issues: </p> |
|---|
| 2014 | <ul> |
|---|
| 2015 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/224">http://tools.ietf.org/wg/httpbis/trac/ticket/224</a>>: "Header Classification" |
|---|
| 2016 | </li> |
|---|
| 2017 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/276">http://tools.ietf.org/wg/httpbis/trac/ticket/276</a>>: "untangle ABNFs for header fields" |
|---|
| 2018 | </li> |
|---|
| 2019 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/277">http://tools.ietf.org/wg/httpbis/trac/ticket/277</a>>: "potentially misleading MAY in media-type def" |
|---|
| 2020 | </li> |
|---|
| 2021 | </ul> |
|---|
| 2022 | <h2 id="rfc.section.E.15"><a href="#rfc.section.E.15">E.15</a> <a id="changes.since.13" href="#changes.since.13">Since draft-ietf-httpbis-p3-payload-13</a></h2> |
|---|
| 2023 | <p id="rfc.section.E.15.p.1">Closed issues: </p> |
|---|
| 2024 | <ul> |
|---|
| 2025 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/20">http://tools.ietf.org/wg/httpbis/trac/ticket/20</a>>: "Default charsets for text media types" |
|---|
| 2026 | </li> |
|---|
| 2027 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/178">http://tools.ietf.org/wg/httpbis/trac/ticket/178</a>>: "Content-MD5 and partial responses" |
|---|
| 2028 | </li> |
|---|
| 2029 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/276">http://tools.ietf.org/wg/httpbis/trac/ticket/276</a>>: "untangle ABNFs for header fields" |
|---|
| 2030 | </li> |
|---|
| 2031 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/281">http://tools.ietf.org/wg/httpbis/trac/ticket/281</a>>: "confusing undefined parameter in media range example" |
|---|
| 2032 | </li> |
|---|
| 2033 | </ul> |
|---|
| 2034 | <h2 id="rfc.section.E.16"><a href="#rfc.section.E.16">E.16</a> <a id="changes.since.14" href="#changes.since.14">Since draft-ietf-httpbis-p3-payload-14</a></h2> |
|---|
| 2035 | <p id="rfc.section.E.16.p.1">None.</p> |
|---|
| 2036 | <h2 id="rfc.section.E.17"><a href="#rfc.section.E.17">E.17</a> <a id="changes.since.15" href="#changes.since.15">Since draft-ietf-httpbis-p3-payload-15</a></h2> |
|---|
| 2037 | <p id="rfc.section.E.17.p.1">Closed issues: </p> |
|---|
| 2038 | <ul> |
|---|
| 2039 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/285">http://tools.ietf.org/wg/httpbis/trac/ticket/285</a>>: "Strength of requirements on Accept re: 406" |
|---|
| 2040 | </li> |
|---|
| 2041 | </ul> |
|---|
| 2042 | <h2 id="rfc.section.E.18"><a href="#rfc.section.E.18">E.18</a> <a id="changes.since.16" href="#changes.since.16">Since draft-ietf-httpbis-p3-payload-16</a></h2> |
|---|
| 2043 | <p id="rfc.section.E.18.p.1">Closed issues: </p> |
|---|
| 2044 | <ul> |
|---|
| 2045 | <li> <<a href="http://tools.ietf.org/wg/httpbis/trac/ticket/186">http://tools.ietf.org/wg/httpbis/trac/ticket/186</a>>: "Document HTTP's error-handling philosophy" |
|---|
| 2046 | </li> |
|---|
| 2047 | </ul> |
|---|
| 2048 | <h1 id="rfc.index"><a href="#rfc.index">Index</a></h1> |
|---|
| 2049 | <p class="noprint"><a href="#rfc.index.A">A</a> <a href="#rfc.index.B">B</a> <a href="#rfc.index.C">C</a> <a href="#rfc.index.D">D</a> <a href="#rfc.index.G">G</a> <a href="#rfc.index.H">H</a> <a href="#rfc.index.M">M</a> <a href="#rfc.index.P">P</a> <a href="#rfc.index.R">R</a> |
|---|
| 2050 | </p> |
|---|
| 2051 | <div class="print2col"> |
|---|
| 2052 | <ul class="ind"> |
|---|
| 2053 | <li><a id="rfc.index.A" href="#rfc.index.A"><b>A</b></a><ul> |
|---|
| 2054 | <li>Accept header field <a href="#rfc.xref.header.accept.1">2.3</a>, <a href="#rfc.xref.header.accept.2">5.1</a>, <a href="#rfc.iref.a.1"><b>6.1</b></a>, <a href="#rfc.xref.header.accept.3">7.1</a></li> |
|---|
| 2055 | <li>Accept-Charset header field <a href="#rfc.xref.header.accept-charset.1">5.1</a>, <a href="#rfc.iref.a.2"><b>6.2</b></a>, <a href="#rfc.xref.header.accept-charset.2">7.1</a>, <a href="#rfc.xref.header.accept-charset.3">C</a></li> |
|---|
| 2056 | <li>Accept-Encoding header field <a href="#rfc.xref.header.accept-encoding.1">2.2</a>, <a href="#rfc.xref.header.accept-encoding.2">5.1</a>, <a href="#rfc.iref.a.3"><b>6.3</b></a>, <a href="#rfc.xref.header.accept-encoding.3">7.1</a>, <a href="#rfc.xref.header.accept-encoding.4">7.2</a></li> |
|---|
| 2057 | <li>Accept-Language header field <a href="#rfc.xref.header.accept-language.1">5.1</a>, <a href="#rfc.iref.a.4"><b>6.4</b></a>, <a href="#rfc.xref.header.accept-language.2">7.1</a></li> |
|---|
| 2058 | </ul> |
|---|
| 2059 | </li> |
|---|
| 2060 | <li><a id="rfc.index.B" href="#rfc.index.B"><b>B</b></a><ul> |
|---|
| 2061 | <li><em>BCP97</em> <a href="#rfc.xref.BCP97.1">10.1</a>, <a href="#rfc.xref.BCP97.2">10.1</a>, <a href="#rfc.xref.BCP97.3">10.1</a>, <a href="#BCP97"><b>10.2</b></a>, <a href="#rfc.xref.BCP97.4">E.5</a></li> |
|---|
| 2062 | </ul> |
|---|
| 2063 | </li> |
|---|
| 2064 | <li><a id="rfc.index.C" href="#rfc.index.C"><b>C</b></a><ul> |
|---|
| 2065 | <li>Coding Format |
|---|
| 2066 | <ul> |
|---|
| 2067 | <li>compress <a href="#rfc.iref.c.3">2.2</a></li> |
|---|
| 2068 | <li>deflate <a href="#rfc.iref.c.4">2.2</a></li> |
|---|
| 2069 | <li>gzip <a href="#rfc.iref.c.5">2.2</a></li> |
|---|
| 2070 | </ul> |
|---|
| 2071 | </li> |
|---|
| 2072 | <li>compress (Coding Format) <a href="#rfc.iref.c.2">2.2</a></li> |
|---|
| 2073 | <li>content negotiation <a href="#rfc.iref.c.1">1.1</a></li> |
|---|
| 2074 | <li>Content-Encoding header field <a href="#rfc.xref.header.content-encoding.1">2.2</a>, <a href="#rfc.xref.header.content-encoding.2">4.1</a>, <a href="#rfc.iref.c.6"><b>6.5</b></a>, <a href="#rfc.xref.header.content-encoding.3">6.5</a>, <a href="#rfc.xref.header.content-encoding.4">7.1</a></li> |
|---|
| 2075 | <li>Content-Language header field <a href="#rfc.xref.header.content-language.1">4.1</a>, <a href="#rfc.iref.c.7"><b>6.6</b></a>, <a href="#rfc.xref.header.content-language.2">7.1</a></li> |
|---|
| 2076 | <li>Content-Location header field <a href="#rfc.xref.header.content-location.1">4.1</a>, <a href="#rfc.iref.c.8"><b>6.7</b></a>, <a href="#rfc.xref.header.content-location.2">7.1</a>, <a href="#rfc.xref.header.content-location.3">C</a></li> |
|---|
| 2077 | <li>Content-Type header field <a href="#rfc.xref.header.content-type.1">2.3</a>, <a href="#rfc.xref.header.content-type.2">4.1</a>, <a href="#rfc.iref.c.9"><b>6.8</b></a>, <a href="#rfc.xref.header.content-type.3">7.1</a></li> |
|---|
| 2078 | </ul> |
|---|
| 2079 | </li> |
|---|
| 2080 | <li><a id="rfc.index.D" href="#rfc.index.D"><b>D</b></a><ul> |
|---|
| 2081 | <li>deflate (Coding Format) <a href="#rfc.iref.d.1">2.2</a></li> |
|---|
| 2082 | </ul> |
|---|
| 2083 | </li> |
|---|
| 2084 | <li><a id="rfc.index.G" href="#rfc.index.G"><b>G</b></a><ul> |
|---|
| 2085 | <li><tt>Grammar</tt> |
|---|
| 2086 | <ul> |
|---|
| 2087 | <li><tt>Accept</tt> <a href="#rfc.iref.g.11"><b>6.1</b></a></li> |
|---|
| 2088 | <li><tt>Accept-Charset</tt> <a href="#rfc.iref.g.15"><b>6.2</b></a></li> |
|---|
| 2089 | <li><tt>Accept-Encoding</tt> <a href="#rfc.iref.g.16"><b>6.3</b></a></li> |
|---|
| 2090 | <li><tt>accept-ext</tt> <a href="#rfc.iref.g.14"><b>6.1</b></a></li> |
|---|
| 2091 | <li><tt>Accept-Language</tt> <a href="#rfc.iref.g.18"><b>6.4</b></a></li> |
|---|
| 2092 | <li><tt>accept-params</tt> <a href="#rfc.iref.g.13"><b>6.1</b></a></li> |
|---|
| 2093 | <li><tt>attribute</tt> <a href="#rfc.iref.g.8"><b>2.3</b></a></li> |
|---|
| 2094 | <li><tt>charset</tt> <a href="#rfc.iref.g.1"><b>2.1</b></a></li> |
|---|
| 2095 | <li><tt>codings</tt> <a href="#rfc.iref.g.17"><b>6.3</b></a></li> |
|---|
| 2096 | <li><tt>content-coding</tt> <a href="#rfc.iref.g.2"><b>2.2</b></a></li> |
|---|
| 2097 | <li><tt>Content-Encoding</tt> <a href="#rfc.iref.g.20"><b>6.5</b></a></li> |
|---|
| 2098 | <li><tt>Content-Language</tt> <a href="#rfc.iref.g.21"><b>6.6</b></a></li> |
|---|
| 2099 | <li><tt>Content-Location</tt> <a href="#rfc.iref.g.22"><b>6.7</b></a></li> |
|---|
| 2100 | <li><tt>Content-Type</tt> <a href="#rfc.iref.g.23"><b>6.8</b></a></li> |
|---|
| 2101 | <li><tt>language-range</tt> <a href="#rfc.iref.g.19"><b>6.4</b></a></li> |
|---|
| 2102 | <li><tt>language-tag</tt> <a href="#rfc.iref.g.10"><b>2.4</b></a></li> |
|---|
| 2103 | <li><tt>media-range</tt> <a href="#rfc.iref.g.12"><b>6.1</b></a></li> |
|---|
| 2104 | <li><tt>media-type</tt> <a href="#rfc.iref.g.4"><b>2.3</b></a></li> |
|---|
| 2105 | <li><tt>MIME-Version</tt> <a href="#rfc.iref.g.24"><b>A.1</b></a></li> |
|---|
| 2106 | <li><tt>parameter</tt> <a href="#rfc.iref.g.7"><b>2.3</b></a></li> |
|---|
| 2107 | <li><tt>subtype</tt> <a href="#rfc.iref.g.6"><b>2.3</b></a></li> |
|---|
| 2108 | <li><tt>type</tt> <a href="#rfc.iref.g.5"><b>2.3</b></a></li> |
|---|
| 2109 | <li><tt>value</tt> <a href="#rfc.iref.g.9"><b>2.3</b></a></li> |
|---|
| 2110 | </ul> |
|---|
| 2111 | </li> |
|---|
| 2112 | <li>gzip (Coding Format) <a href="#rfc.iref.g.3">2.2</a></li> |
|---|
| 2113 | </ul> |
|---|
| 2114 | </li> |
|---|
| 2115 | <li><a id="rfc.index.H" href="#rfc.index.H"><b>H</b></a><ul> |
|---|
| 2116 | <li>Header Fields |
|---|
| 2117 | <ul> |
|---|
| 2118 | <li>Accept <a href="#rfc.xref.header.accept.1">2.3</a>, <a href="#rfc.xref.header.accept.2">5.1</a>, <a href="#rfc.iref.h.1"><b>6.1</b></a>, <a href="#rfc.xref.header.accept.3">7.1</a></li> |
|---|
| 2119 | <li>Accept-Charset <a href="#rfc.xref.header.accept-charset.1">5.1</a>, <a href="#rfc.iref.h.2"><b>6.2</b></a>, <a href="#rfc.xref.header.accept-charset.2">7.1</a>, <a href="#rfc.xref.header.accept-charset.3">C</a></li> |
|---|
| 2120 | <li>Accept-Encoding <a href="#rfc.xref.header.accept-encoding.1">2.2</a>, <a href="#rfc.xref.header.accept-encoding.2">5.1</a>, <a href="#rfc.iref.h.3"><b>6.3</b></a>, <a href="#rfc.xref.header.accept-encoding.3">7.1</a>, <a href="#rfc.xref.header.accept-encoding.4">7.2</a></li> |
|---|
| 2121 | <li>Accept-Language <a href="#rfc.xref.header.accept-language.1">5.1</a>, <a href="#rfc.iref.h.4"><b>6.4</b></a>, <a href="#rfc.xref.header.accept-language.2">7.1</a></li> |
|---|
| 2122 | <li>Content-Encoding <a href="#rfc.xref.header.content-encoding.1">2.2</a>, <a href="#rfc.xref.header.content-encoding.2">4.1</a>, <a href="#rfc.iref.h.5"><b>6.5</b></a>, <a href="#rfc.xref.header.content-encoding.3">6.5</a>, <a href="#rfc.xref.header.content-encoding.4">7.1</a></li> |
|---|
| 2123 | <li>Content-Language <a href="#rfc.xref.header.content-language.1">4.1</a>, <a href="#rfc.iref.h.6"><b>6.6</b></a>, <a href="#rfc.xref.header.content-language.2">7.1</a></li> |
|---|
| 2124 | <li>Content-Location <a href="#rfc.xref.header.content-location.1">4.1</a>, <a href="#rfc.iref.h.7"><b>6.7</b></a>, <a href="#rfc.xref.header.content-location.2">7.1</a>, <a href="#rfc.xref.header.content-location.3">C</a></li> |
|---|
| 2125 | <li>Content-Type <a href="#rfc.xref.header.content-type.1">2.3</a>, <a href="#rfc.xref.header.content-type.2">4.1</a>, <a href="#rfc.iref.h.8"><b>6.8</b></a>, <a href="#rfc.xref.header.content-type.3">7.1</a></li> |
|---|
| 2126 | <li>MIME-Version <a href="#rfc.xref.mime-version.1">7.1</a>, <a href="#rfc.iref.h.9"><b>A.1</b></a></li> |
|---|
| 2127 | </ul> |
|---|
| 2128 | </li> |
|---|
| 2129 | </ul> |
|---|
| 2130 | </li> |
|---|
| 2131 | <li><a id="rfc.index.M" href="#rfc.index.M"><b>M</b></a><ul> |
|---|
| 2132 | <li>MIME-Version header field <a href="#rfc.xref.mime-version.1">7.1</a>, <a href="#rfc.iref.m.1"><b>A.1</b></a></li> |
|---|
| 2133 | </ul> |
|---|
| 2134 | </li> |
|---|
| 2135 | <li><a id="rfc.index.P" href="#rfc.index.P"><b>P</b></a><ul> |
|---|
| 2136 | <li><em>Part1</em> <a href="#rfc.xref.Part1.1">1.2</a>, <a href="#rfc.xref.Part1.2">1.3</a>, <a href="#rfc.xref.Part1.3">1.3.1</a>, <a href="#rfc.xref.Part1.4">1.3.1</a>, <a href="#rfc.xref.Part1.5">1.3.1</a>, <a href="#rfc.xref.Part1.6">1.3.1</a>, <a href="#rfc.xref.Part1.7">1.3.2</a>, <a href="#rfc.xref.Part1.8">1.3.2</a>, <a href="#rfc.xref.Part1.9">1.3.2</a>, <a href="#rfc.xref.Part1.10">2.2</a>, <a href="#rfc.xref.Part1.11">2.2</a>, <a href="#rfc.xref.Part1.12">2.2</a>, <a href="#rfc.xref.Part1.13">2.2.1</a>, <a href="#rfc.xref.Part1.14">2.2.1</a>, <a href="#rfc.xref.Part1.15">3.1</a>, <a href="#rfc.xref.Part1.16">3.2</a>, <a href="#rfc.xref.Part1.17">5.1</a>, <a href="#rfc.xref.Part1.18">6.1</a>, <a href="#rfc.xref.Part1.19">6.3</a>, <a href="#rfc.xref.Part1.20">6.7</a>, <a href="#rfc.xref.Part1.21">7.2</a>, <a href="#rfc.xref.Part1.22">7.2</a>, <a href="#rfc.xref.Part1.23">7.2</a>, <a href="#rfc.xref.Part1.24">9</a>, <a href="#Part1"><b>10.1</b></a>, <a href="#rfc.xref.Part1.25">A.6</a><ul> |
|---|
| 2137 | <li><em>Section 1.2</em> <a href="#rfc.xref.Part1.2">1.3</a></li> |
|---|
| 2138 | <li><em>Section 1.2.2</em> <a href="#rfc.xref.Part1.4">1.3.1</a></li> |
|---|
| 2139 | <li><em>Section 2</em> <a href="#rfc.xref.Part1.1">1.2</a></li> |
|---|
| 2140 | <li><em>Section 2.7</em> <a href="#rfc.xref.Part1.7">1.3.2</a>, <a href="#rfc.xref.Part1.8">1.3.2</a></li> |
|---|
| 2141 | <li><em>Section 3.2.3</em> <a href="#rfc.xref.Part1.5">1.3.1</a>, <a href="#rfc.xref.Part1.6">1.3.1</a></li> |
|---|
| 2142 | <li><em>Section 3.3</em> <a href="#rfc.xref.Part1.16">3.2</a></li> |
|---|
| 2143 | <li><em>Section 4.3</em> <a href="#rfc.xref.Part1.20">6.7</a></li> |
|---|
| 2144 | <li><em>Section 5.1</em> <a href="#rfc.xref.Part1.13">2.2.1</a></li> |
|---|
| 2145 | <li><em>Section 5.1.2.1</em> <a href="#rfc.xref.Part1.10">2.2</a>, <a href="#rfc.xref.Part1.21">7.2</a></li> |
|---|
| 2146 | <li><em>Section 5.1.2</em> <a href="#rfc.xref.Part1.14">2.2.1</a></li> |
|---|
| 2147 | <li><em>Section 5.1.2.2</em> <a href="#rfc.xref.Part1.11">2.2</a>, <a href="#rfc.xref.Part1.22">7.2</a></li> |
|---|
| 2148 | <li><em>Section 5.1.2.3</em> <a href="#rfc.xref.Part1.12">2.2</a>, <a href="#rfc.xref.Part1.23">7.2</a></li> |
|---|
| 2149 | <li><em>Section 5.3</em> <a href="#rfc.xref.Part1.9">1.3.2</a>, <a href="#rfc.xref.Part1.17">5.1</a>, <a href="#rfc.xref.Part1.18">6.1</a>, <a href="#rfc.xref.Part1.19">6.3</a></li> |
|---|
| 2150 | <li><em>Section 8.2</em> <a href="#rfc.xref.Part1.15">3.1</a></li> |
|---|
| 2151 | <li><em>Section 8.6</em> <a href="#rfc.xref.Part1.25">A.6</a></li> |
|---|
| 2152 | <li><em>Section 11</em> <a href="#rfc.xref.Part1.24">9</a></li> |
|---|
| 2153 | </ul> |
|---|
| 2154 | </li> |
|---|
| 2155 | <li><em>Part2</em> <a href="#rfc.xref.Part2.1">5.1</a>, <a href="#Part2"><b>10.1</b></a>, <a href="#rfc.xref.Part2.2">A.3</a><ul> |
|---|
| 2156 | <li><em>Section 8</em> <a href="#rfc.xref.Part2.2">A.3</a></li> |
|---|
| 2157 | <li><em>Section 9.10</em> <a href="#rfc.xref.Part2.1">5.1</a></li> |
|---|
| 2158 | </ul> |
|---|
| 2159 | </li> |
|---|
| 2160 | <li><em>Part4</em> <a href="#rfc.xref.Part4.1">4.1</a>, <a href="#Part4"><b>10.1</b></a><ul> |
|---|
| 2161 | <li><em>Section 2.2</em> <a href="#rfc.xref.Part4.1">4.1</a></li> |
|---|
| 2162 | </ul> |
|---|
| 2163 | </li> |
|---|
| 2164 | <li><em>Part5</em> <a href="#rfc.xref.Part5.1">3.1</a>, <a href="#Part5"><b>10.1</b></a><ul> |
|---|
| 2165 | <li><em>Section 5.2</em> <a href="#rfc.xref.Part5.1">3.1</a></li> |
|---|
| 2166 | </ul> |
|---|
| 2167 | </li> |
|---|
| 2168 | <li><em>Part6</em> <a href="#rfc.xref.Part6.1">4.1</a>, <a href="#rfc.xref.Part6.2">5.1</a>, <a href="#Part6"><b>10.1</b></a><ul> |
|---|
| 2169 | <li><em>Section 3.3</em> <a href="#rfc.xref.Part6.1">4.1</a></li> |
|---|
| 2170 | <li><em>Section 3.5</em> <a href="#rfc.xref.Part6.2">5.1</a></li> |
|---|
| 2171 | </ul> |
|---|
| 2172 | </li> |
|---|
| 2173 | <li>payload <a href="#rfc.iref.p.1">3</a></li> |
|---|
| 2174 | </ul> |
|---|
| 2175 | </li> |
|---|
| 2176 | <li><a id="rfc.index.R" href="#rfc.index.R"><b>R</b></a><ul> |
|---|
| 2177 | <li>representation <a href="#rfc.iref.r.1">4</a></li> |
|---|
| 2178 | <li><em>RFC1945</em> <a href="#RFC1945"><b>10.2</b></a>, <a href="#rfc.xref.RFC1945.1">B</a></li> |
|---|
| 2179 | <li><em>RFC1950</em> <a href="#rfc.xref.RFC1950.1">7.2</a>, <a href="#RFC1950"><b>10.1</b></a></li> |
|---|
| 2180 | <li><em>RFC1951</em> <a href="#rfc.xref.RFC1951.1">7.2</a>, <a href="#RFC1951"><b>10.1</b></a></li> |
|---|
| 2181 | <li><em>RFC1952</em> <a href="#rfc.xref.RFC1952.1">7.2</a>, <a href="#RFC1952"><b>10.1</b></a></li> |
|---|
| 2182 | <li><em>RFC2045</em> <a href="#RFC2045"><b>10.1</b></a>, <a href="#rfc.xref.RFC2045.1">A</a>, <a href="#rfc.xref.RFC2045.2">A.1</a></li> |
|---|
| 2183 | <li><em>RFC2046</em> <a href="#rfc.xref.RFC2046.1">2.3</a>, <a href="#rfc.xref.RFC2046.2">2.3.2</a>, <a href="#rfc.xref.RFC2046.3">4.2</a>, <a href="#RFC2046"><b>10.1</b></a>, <a href="#rfc.xref.RFC2046.4">A.2</a><ul> |
|---|
| 2184 | <li><em>Section 4.5.1</em> <a href="#rfc.xref.RFC2046.3">4.2</a></li> |
|---|
| 2185 | <li><em>Section 5.1.1</em> <a href="#rfc.xref.RFC2046.2">2.3.2</a></li> |
|---|
| 2186 | </ul> |
|---|
| 2187 | </li> |
|---|
| 2188 | <li><em>RFC2049</em> <a href="#RFC2049"><b>10.2</b></a>, <a href="#rfc.xref.RFC2049.1">A.2</a><ul> |
|---|
| 2189 | <li><em>Section 4</em> <a href="#rfc.xref.RFC2049.1">A.2</a></li> |
|---|
| 2190 | </ul> |
|---|
| 2191 | </li> |
|---|
| 2192 | <li><em>RFC2068</em> <a href="#rfc.xref.RFC2068.1">10.1</a>, <a href="#rfc.xref.RFC2068.2">10.1</a>, <a href="#rfc.xref.RFC2068.3">10.1</a>, <a href="#RFC2068"><b>10.2</b></a>, <a href="#rfc.xref.RFC2068.4">B</a></li> |
|---|
| 2193 | <li><em>RFC2076</em> <a href="#RFC2076"><b>10.2</b></a>, <a href="#rfc.xref.RFC2076.1">B</a></li> |
|---|
| 2194 | <li><em>RFC2119</em> <a href="#rfc.xref.RFC2119.1">1.2</a>, <a href="#RFC2119"><b>10.1</b></a></li> |
|---|
| 2195 | <li><em>RFC2277</em> <a href="#rfc.xref.RFC2277.1">2.1</a>, <a href="#RFC2277"><b>10.2</b></a></li> |
|---|
| 2196 | <li><em>RFC2295</em> <a href="#rfc.xref.RFC2295.1">5</a>, <a href="#RFC2295"><b>10.2</b></a></li> |
|---|
| 2197 | <li><em>RFC2388</em> <a href="#rfc.xref.RFC2388.1">2.3.2</a>, <a href="#RFC2388"><b>10.2</b></a></li> |
|---|
| 2198 | <li><em>RFC2557</em> <a href="#rfc.xref.RFC2557.1">6.7</a>, <a href="#RFC2557"><b>10.2</b></a>, <a href="#rfc.xref.RFC2557.2">A.7</a><ul> |
|---|
| 2199 | <li><em>Section 4</em> <a href="#rfc.xref.RFC2557.1">6.7</a></li> |
|---|
| 2200 | </ul> |
|---|
| 2201 | </li> |
|---|
| 2202 | <li><em>RFC2616</em> <a href="#rfc.xref.RFC2616.1">1</a>, <a href="#rfc.xref.RFC2616.2">6.4</a>, <a href="#RFC2616"><b>10.2</b></a>, <a href="#rfc.xref.RFC2616.3">E.1</a><ul> |
|---|
| 2203 | <li><em>Section 14.4</em> <a href="#rfc.xref.RFC2616.2">6.4</a></li> |
|---|
| 2204 | </ul> |
|---|
| 2205 | </li> |
|---|
| 2206 | <li><em>RFC3629</em> <a href="#rfc.xref.RFC3629.1">2.1</a>, <a href="#RFC3629"><b>10.2</b></a></li> |
|---|
| 2207 | <li><em>RFC3864</em> <a href="#rfc.xref.RFC3864.1">7.1</a>, <a href="#RFC3864"><b>10.2</b></a></li> |
|---|
| 2208 | <li><em>RFC4288</em> <a href="#rfc.xref.RFC4288.1">2.3</a>, <a href="#RFC4288"><b>10.2</b></a></li> |
|---|
| 2209 | <li><em>RFC4647</em> <a href="#rfc.xref.RFC4647.1">6.4</a>, <a href="#rfc.xref.RFC4647.2">6.4</a>, <a href="#rfc.xref.RFC4647.3">6.4</a>, <a href="#rfc.xref.RFC4647.4">6.4</a>, <a href="#RFC4647"><b>10.1</b></a><ul> |
|---|
| 2210 | <li><em>Section 2.1</em> <a href="#rfc.xref.RFC4647.1">6.4</a></li> |
|---|
| 2211 | <li><em>Section 2.3</em> <a href="#rfc.xref.RFC4647.2">6.4</a></li> |
|---|
| 2212 | <li><em>Section 3</em> <a href="#rfc.xref.RFC4647.3">6.4</a></li> |
|---|
| 2213 | <li><em>Section 3.3.1</em> <a href="#rfc.xref.RFC4647.4">6.4</a></li> |
|---|
| 2214 | </ul> |
|---|
| 2215 | </li> |
|---|
| 2216 | <li><em>RFC5226</em> <a href="#rfc.xref.RFC5226.1">2.2.1</a>, <a href="#RFC5226"><b>10.2</b></a><ul> |
|---|
| 2217 | <li><em>Section 4.1</em> <a href="#rfc.xref.RFC5226.1">2.2.1</a></li> |
|---|
| 2218 | </ul> |
|---|
| 2219 | </li> |
|---|
| 2220 | <li><em>RFC5234</em> <a href="#rfc.xref.RFC5234.1">1.3</a>, <a href="#rfc.xref.RFC5234.2">1.3</a>, <a href="#RFC5234"><b>10.1</b></a><ul> |
|---|
| 2221 | <li><em>Appendix B.1</em> <a href="#rfc.xref.RFC5234.2">1.3</a></li> |
|---|
| 2222 | </ul> |
|---|
| 2223 | </li> |
|---|
| 2224 | <li><em>RFC5322</em> <a href="#RFC5322"><b>10.2</b></a>, <a href="#rfc.xref.RFC5322.1">A</a></li> |
|---|
| 2225 | <li><em>RFC5646</em> <a href="#rfc.xref.RFC5646.1">2.4</a>, <a href="#rfc.xref.RFC5646.2">2.4</a>, <a href="#rfc.xref.RFC5646.3">2.4</a>, <a href="#RFC5646"><b>10.1</b></a><ul> |
|---|
| 2226 | <li><em>Section 2.1</em> <a href="#rfc.xref.RFC5646.2">2.4</a></li> |
|---|
| 2227 | </ul> |
|---|
| 2228 | </li> |
|---|
| 2229 | <li><em>RFC6151</em> <a href="#RFC6151"><b>10.2</b></a>, <a href="#rfc.xref.RFC6151.1">C</a></li> |
|---|
| 2230 | <li><em>RFC6266</em> <a href="#RFC6266"><b>10.2</b></a>, <a href="#rfc.xref.RFC6266.1">B</a>, <a href="#rfc.xref.RFC6266.2">C</a></li> |
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| 2231 | </ul> |
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| 2232 | </li> |
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| 2233 | </ul> |
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| 2234 | </div> |
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| 2235 | </body> |
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| 2236 | </html> |
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